Gout and pseudogout are both characterized by the presence of crystal deposits in the joints that are affected. Gout occurs when urate crystals are deposited, while pseudogout occurs when calcium pyrophosphate crystals are deposited. Under a microscope, these crystals can be distinguished by their appearance. Urate crystals are needle-shaped and negatively birefringent, while calcium pyrophosphate crystals are brick-shaped and positively birefringent.

Gout can affect any joint in the body, but it most commonly manifests in the hallux metatarsophalangeal joint, which is the joint at the base of the big toe. This joint is affected in approximately 50% of gout cases. On the other hand, pseudogout primarily affects the larger joints, such as the knee.

Spondyloarthritis is a term that encompasses various inflammatory conditions affecting both the joints and the entheses, which are the attachment sites of ligaments and tendons to the bones. The primary cause of spondyloarthritis is ankylosing spondylitis, but it can also be triggered by reactive arthritis, psoriatic arthritis, and enteropathic arthropathies.

If individuals below the age of 45 experience four or more of the following symptoms, they should be referred for a potential diagnosis of spondyloarthritis:

– Presence of low back pain and being younger than 35 years old
– Waking up in the second half of the night due to pain
– Buttock pain
– Pain that improves with movement or within 48 hours of using nonsteroidal anti-inflammatory drugs (NSAIDs)
– Having a first-degree relative with spondyloarthritis
– History of current or past arthritis, psoriasis, or enthesitis.

This patient has presented with an Addisonian crisis, which is a rare but potentially catastrophic condition if not diagnosed promptly. It is more commonly seen in women than men and typically occurs between the ages of 30 and 50.

Addison’s disease is caused by insufficient production of steroid hormones by the adrenal glands, affecting the production of glucocorticoids, mineralocorticoids, and sex steroids. The main causes of Addison’s disease include autoimmune adrenalitis (accounting for 80% of cases), bilateral adrenalectomy, Waterhouse-Friderichsen syndrome (hemorrhage into the adrenal glands), and tuberculosis.

The most common trigger for an Addisonian crisis in patients with Addison’s disease is the intentional or accidental withdrawal of steroid therapy. Other factors that can precipitate a crisis include infection, trauma, myocardial infarction, cerebral infarction, asthma, hypothermia, and alcohol abuse.

Clinical features of Addison’s disease include weakness, lethargy, hypotension (especially orthostatic hypotension), nausea, vomiting, weight loss, reduced axillary and pubic hair, depression, and hyperpigmentation (particularly in palmar creases, buccal mucosa, and exposed areas). In an Addisonian crisis, the main symptoms are usually hypoglycemia and shock, characterized by tachycardia, peripheral vasoconstriction, hypotension, altered consciousness, and even coma.

Biochemical markers of Addison’s disease typically include increased ACTH levels (as a compensatory response to stimulate the adrenal glands), elevated serum renin levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Confirmatory investigations may involve the Synacthen test, plasma ACTH level measurement, plasma renin level measurement, and testing for adrenocortical antibodies.

Management of Addison’s disease should be overseen by an Endocrinologist. Treatment usually involves the administration of hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also require thyroxine if there is concurrent hypothalamic-pituitary disease. Treatment is lifelong, and patients should carry a steroid card and MedicAlert bracelet to alert healthcare professionals about their condition and the potential for an Addisonian crisis.

Peptic ulcer disease is most commonly caused by NSAIDs, making them the leading drug cause. However, h.pylori infection is the primary cause of peptic ulcers, with NSAIDs being the second most common cause.

Further Reading:

Peptic ulcer disease (PUD) is a condition characterized by a break in the mucosal lining of the stomach or duodenum. It is caused by an imbalance between factors that promote mucosal damage, such as gastric acid, pepsin, Helicobacter pylori infection, and NSAID drug use, and factors that maintain mucosal integrity, such as prostaglandins, mucus lining, bicarbonate, and mucosal blood flow.

The most common causes of peptic ulcers are H. pylori infection and NSAID use. Other factors that can contribute to the development of ulcers include smoking, alcohol consumption, certain medications (such as steroids), stress, autoimmune conditions, and tumors.

Diagnosis of peptic ulcers involves screening for H. pylori infection through breath or stool antigen tests, as well as upper gastrointestinal endoscopy. Complications of PUD include bleeding, perforation, and obstruction. Acute massive hemorrhage has a case fatality rate of 5-10%, while perforation can lead to peritonitis with a mortality rate of up to 20%.

The symptoms of peptic ulcers vary depending on their location. Duodenal ulcers typically cause pain that is relieved by eating, occurs 2-3 hours after eating and at night, and may be accompanied by nausea and vomiting. Gastric ulcers, on the other hand, cause pain that occurs 30 minutes after eating and may be associated with nausea and vomiting.

Management of peptic ulcers depends on the underlying cause and presentation. Patients with active gastrointestinal bleeding require risk stratification, volume resuscitation, endoscopy, and proton pump inhibitor (PPI) therapy. Those with perforated ulcers require resuscitation, antibiotic treatment, analgesia, PPI therapy, and urgent surgical review.

For stable patients with peptic ulcers, lifestyle modifications such as weight loss, avoiding trigger foods, eating smaller meals, quitting smoking, reducing alcohol consumption, and managing stress and anxiety are recommended. Medication review should be done to stop causative drugs if possible. PPI therapy, with or without H. pylori eradication therapy, is also prescribed. H. pylori testing is typically done using a carbon-13 urea breath test or stool antigen test, and eradication therapy involves a 7-day triple therapy regimen of antibiotics and PPI.

Lidocaine is commonly chosen because it offers some local anesthesia. Alternatively, mineral oil can be used. Cold water irrigation can often cause nausea and vomiting, so it is recommended to use warm water for irrigation. An ENT clinician should be able to remove an insect from the ear canal. However, if removal attempts are unsuccessful or complications arise, a referral may be necessary.

Further Reading:

Foreign bodies in the ear or nose are a common occurrence, especially in children between the ages of 2 and 8. Foreign bodies in the ear are more common than those in the nose. Symptoms of foreign bodies in the ear may include ear pain, a feeling of fullness, impaired hearing, discharge, tinnitus, and vertigo. It is important to consider referral to an ENT specialist for the removal of potentially harmful foreign bodies such as glass, sharp objects, button batteries, and tightly wedged items. ENT involvement is also necessary if there is a perforation of the eardrum or if the foreign body is embedded in the eardrum.

When preparing a patient for removal, it is important to establish rapport and keep the patient relaxed, especially if they are a young child. The patient should be positioned comfortably and securely, and ear drops may be used to anesthetize the ear. Removal methods for foreign bodies in the ear include the use of forceps or a hook, irrigation (except for batteries, perforations, or organic material), suction, and magnets for ferrous metal foreign bodies. If there is an insect in the ear, it should be killed with alcohol, lignocaine, or mineral oil before removal.

After the foreign body is removed, it is important to check for any residual foreign bodies and to discharge the patient with appropriate safety net advice. Prophylactic antibiotic drops may be considered if there has been an abrasion of the skin.

Foreign bodies in the nose are less common but should be dealt with promptly due to the risk of posterior dislodgement into the airway. Symptoms of foreign bodies in the nose may include nasal discharge, sinusitis, nasal pain, epistaxis, or blood-stained discharge. Most nasal foreign bodies are found on the anterior or middle third of the nose and may not show up on x-rays.

Methods for removing foreign bodies from the nose include the mother’s kiss technique, suction, forceps, Jobson horne probe, and foley catheter. The mother’s kiss technique involves occluding the patent nostril and having a parent blow into the patient’s mouth. A foley catheter can be used by inserting it past the foreign body and inflating the balloon to gently push the foreign body out. ENT referral may be necessary if the foreign body cannot be visualized but there is a high suspicion, if attempts to remove the foreign body have failed, if the patient requires sed

Vestibular neuronitis is characterized by the sudden and prolonged onset of rotational vertigo. This vertigo can occur spontaneously, upon waking up, or gradually worsen throughout the day. It is particularly aggravated by changes in head position, although it remains constant even when the head is still. Unlike other conditions, vestibular neuronitis does not cause hearing loss, tinnitus, or focal neurological deficits. On the other hand, in BPPV, episodes of vertigo are usually brief, lasting less than 20 seconds, and only occur when there is a change in head position.

Further Reading:

Vestibular neuritis, also known as vestibular neuronitis, is a condition characterized by sudden and prolonged vertigo of peripheral origin. It is believed to be caused by inflammation of the vestibular nerve, often following a viral infection. It is important to note that vestibular neuritis and labyrinthitis are not the same condition, as labyrinthitis involves inflammation of the labyrinth. Vestibular neuritis typically affects individuals between the ages of 30 and 60, with a 1:1 ratio of males to females. The annual incidence is approximately 3.5 per 100,000 people, making it one of the most commonly diagnosed causes of vertigo.

Clinical features of vestibular neuritis include nystagmus, which is a rapid, involuntary eye movement, typically in a horizontal or horizontal-torsional direction away from the affected ear. The head impulse test may also be positive. Other symptoms include spontaneous onset of rotational vertigo, which is worsened by changes in head position, as well as nausea, vomiting, and unsteadiness. These severe symptoms usually last for 2-3 days, followed by a gradual recovery over a few weeks. It is important to note that hearing is not affected in vestibular neuritis, and symptoms such as tinnitus and focal neurological deficits are not present.

Differential diagnosis for vestibular neuritis includes benign paroxysmal positional vertigo (BPPV), labyrinthitis, Meniere’s disease, migraine, stroke, and cerebellar lesions. Management of vestibular neuritis involves drug treatment for nausea and vomiting associated with vertigo, typically through short courses of medication such as prochlorperazine or cyclizine. If symptoms are severe and fluids cannot be tolerated, admission and administration of IV fluids may be necessary. General advice should also be given, including avoiding driving while symptomatic, considering the suitability to work based on occupation and duties, and the increased risk of falls. Follow-up is required, and referral is necessary if there are atypical symptoms, symptoms do not improve after a week of treatment, or symptoms persist for more than 6 weeks.

The prognosis for vestibular neuritis is generally good, with the majority of individuals fully recovering within 6 weeks. Recurrence is thought to occur in 2-11% of cases, and approximately 10% of individuals may develop BPPV following an episode of vestibular neuritis. A very rare complication of vestibular neuritis is ph

Brugada syndrome is a genetic disorder that is passed down from one generation to another in an autosomal dominant manner. It is characterized by abnormal findings on an electrocardiogram (ECG) and can lead to sudden cardiac death. The cause of death in individuals with Brugada syndrome is typically ventricular fibrillation, which occurs as a result of specific defects in ion channels that are determined by our genes. Interestingly, this syndrome is more commonly observed in South East Asia and is actually the leading cause of sudden unexplained cardiac death in Thailand.

One of the key features seen on an ECG that is consistent with Type 1 Brugada syndrome is a pattern known as right bundle branch block. Additionally, there is a distinct downward sloping coved ST elevation observed in leads V1-V3. These specific ECG findings help to identify individuals who may be at risk for developing Brugada syndrome and experiencing its potentially fatal consequences.

This man is at high risk of contracting HIV due to his history of intravenous drug abuse and sharing needles. If a patient has a flu-like illness and a history of risk factors, it is important to suspect that they may be experiencing an HIV seroconversion illness.

Around 20-60% of individuals who contract HIV go through a seroconversion illness. This typically occurs within 1 to 6 weeks after exposure and presents with symptoms similar to the flu. Common clinical features include fever, malaise, myalgia, pharyngitis, diarrhea, headaches, maculopapular rash, lymphadenopathy, and neuralgia.

During this stage of the disease, antibody tests will show negative results. However, a diagnosis of HIV can still be made by conducting a P24 antigen test or measuring HIV RNA levels. CD4 and CD8 counts are usually within the normal range at this stage.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 individuals. It occurs due to a deficiency in Von Willebrand factor (vWF), which plays a crucial role in blood clotting. vWF not only binds to factor VIII to protect it from rapid breakdown, but it is also necessary for proper platelet adhesion. When vWF is lacking, both factor VIII levels and platelet function are affected, leading to prolonged APTT and bleeding time. However, the platelet count and thrombin time remain unaffected.

While some individuals with vWD may not experience any symptoms and are diagnosed incidentally during a clotting profile check, others may present with easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be managed with desmopressin. This medication works by stimulating the release of vWF stored in the Weibel-Palade bodies, which are storage granules found in the endothelial cells lining the blood vessels and heart. By increasing the patient’s own levels of vWF, desmopressin helps improve clotting. In more severe cases, replacement therapy is necessary. This involves infusing cryoprecipitate or Factor VIII concentrate to provide the missing vWF. Replacement therapy is particularly recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

The Alcohol Use Disorder Identification Test (AUDIT) has been developed by the World Health Organization as a straightforward screening tool to detect early signs of hazardous and harmful drinking, as well as mild dependence. This assessment is more comprehensive than the CAGE questionnaire and is currently recommended by NICE for identifying alcohol misuse.

NICE, the National Institute for Health and Care Excellence, suggests the use of specific assessment tools to evaluate the nature and severity of alcohol misuse. These tools include AUDIT for identification and as a routine outcome measure, SADQ or LDQ for assessing the severity of dependence, CIWA-Ar for evaluating the severity of withdrawal symptoms, and APQ for understanding the nature and extent of problems resulting from alcohol misuse.

For more information on this topic, you can refer to the NICE guidance titled Alcohol-use disorders: diagnosis, assessment and management of harmful drinking and alcohol dependence.

According to NICE, one of the recommended treatments for mild-to-moderate Alzheimer’s disease is the use of acetylcholinesterase (AChE) inhibitors. These inhibitors include Donepezil (Aricept), Galantamine, and Rivastigmine. They work by inhibiting the enzyme that breaks down acetylcholine, a neurotransmitter involved in memory and cognitive function.

On the other hand, Memantine is a different type of medication that acts by blocking NMDA-type glutamate receptors. It is recommended for patients with moderate Alzheimer’s disease who cannot tolerate or have a contraindication to AChE inhibitors, or for those with severe Alzheimer’s disease.

The diagnosis in this case is non-alcoholic steatohepatitis (NASH), which is characterized by fatty infiltration of the liver and is commonly associated with obesity. It is the most frequent cause of persistently elevated ALT levels in patients without risk factors for chronic liver disease.

Risk factors for developing NASH include obesity, particularly truncal obesity, diabetes mellitus, and hypercholesterolemia.

The clinical features of NASH can vary, with many patients being completely asymptomatic. However, some may experience right upper quadrant pain, nausea and vomiting, and hepatomegaly (enlarged liver).

The typical biochemical profile seen in NASH includes elevated transaminases, with an AST:ALT ratio of less than 1. Often, there is an isolated elevation of ALT, and gamma-GT levels may be mildly elevated. In about one-third of patients, non-organ specific autoantibodies may be present. The presence of antinuclear antibodies (ANA) is associated with insulin resistance and indicates a higher risk of rapid progression to advanced liver disease.

If the AST level is significantly elevated or if the gamma-GT level is markedly elevated, further investigation for other potential causes should be considered. A markedly elevated gamma-GT level may suggest alcohol abuse, although it can also be elevated in NASH alone.

Diagnosis of NASH is confirmed through a liver biopsy, which will reveal increased fat deposition and a necro-inflammatory response within the hepatocytes.

Currently, there is no specific treatment for NASH. However, weight loss and medications that improve insulin resistance, such as metformin, may help slow down the progression of the disease.

Hypertension, hyperglycemia, weight gain, truncal obesity, supraclavicular fat pads, and striae are characteristic symptoms of a Cushing syndrome.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

Extrapyramidal side effects are most commonly seen with the piperazine phenothiazines (fluphenazine, prochlorperazine, and trifluoperazine) and butyrophenones (benperidol and haloperidol). Among these, haloperidol is the most frequently implicated antipsychotic drug.

Tardive dyskinesia, which involves rhythmic and involuntary movements of the tongue, face, and jaw, typically develops after long-term treatment or high doses. It is the most severe manifestation of extrapyramidal symptoms, as it may become irreversible even after discontinuing the causative drug, and treatment options are generally ineffective.

Dystonia, characterized by abnormal movements of the face and body, is more commonly observed in children and young adults and tends to occur after only a few doses. Acute dystonia can be managed with intravenous administration of procyclidine (5 mg) or benzatropine (2 mg) as a bolus.

Akathisia refers to an unpleasant sensation of restlessness, while akinesia refers to an inability to initiate movement.

Elderly patients with dementia-related psychosis who are treated with haloperidol have an increased risk of mortality. This is believed to be due to a higher likelihood of experiencing cardiovascular events and infections such as pneumonia.

The pupillary light reflex is a reflex that regulates the size of the pupil in response to the intensity of light that reaches the retina. It consists of two separate pathways, the afferent pathway and the efferent pathway.

The afferent pathway begins with light entering the pupil and stimulating the retinal ganglion cells in the retina. These cells then transmit the light signal to the optic nerve. At the optic chiasm, the nasal retinal fibers cross to the opposite optic tract, while the temporal retinal fibers remain in the same optic tract. The fibers from the optic tracts then project and synapse in the pretectal nuclei in the dorsal midbrain. From there, the pretectal nuclei send fibers to the ipsilateral Edinger-Westphal nucleus via the posterior commissure.

On the other hand, the efferent pathway starts with the Edinger-Westphal nucleus projecting preganglionic parasympathetic fibers. These fibers exit the midbrain and travel along the oculomotor nerve. They then synapse on post-ganglionic parasympathetic fibers in the ciliary ganglion. The post-ganglionic fibers, known as the short ciliary nerves, innervate the sphincter muscle of the pupils, causing them to constrict.

The result of these pathways is that when light is shone in one eye, both the direct pupillary light reflex (ipsilateral eye) and the consensual pupillary light reflex (contralateral eye) occur.

Lesions affecting the pupillary light reflex can be identified by comparing the direct and consensual reactions to light in both eyes. If the optic nerve of the first eye is damaged, both the direct and consensual reflexes in the second eye will be lost. However, when light is shone into the second eye, the pupil of the first eye will still constrict. If the optic nerve of the second eye is damaged, the second eye will constrict consensually when light is shone into the unaffected first eye. If the oculomotor nerve of the first eye is damaged, the first eye will have no direct light reflex, but the second eye will still constrict consensually. Finally, if the oculomotor nerve of the second eye is damaged, there will be no consensual constriction of the second eye when light is shone into the unaffected first eye.

Two types of tapeworms, Taenia solium and Taenia saginata, can infest humans. Infestation occurs when people consume meat from intermediate hosts that contain the parasite’s tissue stages. Tapeworms compete for nutrients and infestation is often without symptoms. However, in more severe cases, individuals may experience epigastric pain, diarrhea, and vomiting. Diagnosis involves identifying characteristic eggs in the patient’s stool.

Taenia solium infestation can also lead to a condition called cysticercosis. This occurs when larval cysts infiltrate and spread throughout the lung, liver, eye, or brain. Cysticercosis presents with neurological symptoms, seizures, and impaired vision. Confirmation of cysticercosis involves the presence of antibodies and imaging tests such as chest X-rays and CT brain scans.

The treatment for tapeworm infestation is highly effective and involves the use of medications like niclosamide or praziquantel. However, it is important to seek specialist advice when managing Taenia infections in the central nervous system, as severe inflammatory reactions can occur.

This patient has been diagnosed with severe hyperkalemia and is showing significant ECG changes. The top priority in this situation is to protect the heart. It is recommended to administer 10 ml of 10% calcium chloride immediately over a period of 2-5 minutes. Calcium helps counteract the harmful effects of hyperkalemia on the heart by stabilizing the cardiac cell membrane and preventing unwanted depolarization.

Hyperkalemia is a commonly encountered electrolyte disorder, affecting up to 10% of hospitalized patients. It is typically caused by an increase in potassium release from cells or impaired excretion by the kidneys. The main causes of hyperkalemia include renal failure, certain medications (such as ACE inhibitors, ARBs, potassium-sparing diuretics, and NSAIDs), tissue breakdown (as seen in conditions like tumor lysis, rhabdomyolysis, and hemolysis), metabolic acidosis (often associated with renal failure or diabetic ketoacidosis), and endocrine disorders like Addison’s disease.

ECG changes that may be observed in hyperkalemia include a prolonged PR interval, peaked T-waves, widening of the QRS complex, reduced or absent P wave, sine wave pattern, AV dissociation, asystole, and bradycardia. It is important to note that the severity of ECG changes may not always correlate with the actual serum potassium levels in a patient.

The treatment approach for hyperkalemia depends on its severity. Mild hyperkalemia is defined as a potassium level of 5.5-5.9 mmol/L, moderate hyperkalemia as 6.0-6.4 mmol/L, and severe hyperkalemia as >6.5 mmol/L.

For mild hyperkalemia, the focus should be on addressing the underlying cause and preventing further increase in serum potassium levels. This may involve adjusting medications or dietary changes. If treatment is necessary, potassium exchange resins like calcium resonium can be used to remove potassium from the body.

In cases of moderate hyperkalemia, the goal is to shift potassium from the extracellular space into the cells. This can be achieved by administering insulin and glucose intravenously. Monitoring blood glucose levels is crucial in this situation. Potassium exchange resins should also be considered, and dialysis may be necessary.

Severe hyperkalemia without ECG changes requires immediate medical attention.

Fifth disease, also known as ‘slapped cheek syndrome’, is a common childhood exanthem caused by parvovirus B19.

The clinical features of fifth disease include:

– A mild coryzal illness usually occurs as a prodrome.
– The classic ‘slapped cheek’ rash appears after 3-7 days, characterized by a red rash on the cheeks with pale skin around the mouth.
– A morbilliform rash develops on the extensor surfaces of the arms and legs 1-4 days after the facial rash appears.

This disease is generally harmless and resolves on its own in children. However, it can be dangerous for pregnant women who are exposed to the virus, as it can cause intrauterine infection and hydrops fetalis. Additionally, it can lead to transient aplastic crisis. Therefore, it is important to keep affected children away from pregnant women and individuals with weakened immune systems or blood disorders.

Lidocaine is a tertiary amine that is primarily utilized as a local anesthetic. It can also be employed in the treatment of ventricular arrhythmias. The mechanism of action of lidocaine as a local anesthetic involves its diffusion in the form of an uncharged base through neural sheaths and the axonal membrane. It then reaches the internal surface of the cell membrane sodium channels, where it exerts its effect by blocking the fast voltage-gated sodium channels. This alteration in signal conduction prevents the depolarization of the postsynaptic neuron’s membrane, thereby inhibiting the transmission of pain signals.

In a plain 1% lidocaine solution, each 1 ml contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg, with a maximum limit of 200 mg. However, when administered with adrenaline in a 1:200,000 ratio, the maximum safe dose increases to 7 mg/kg, with a maximum limit of 500 mg. It is important to note that the combination of lidocaine and adrenaline should not be used in extremities such as fingers, toes, and the nose due to the risk of vasoconstriction and tissue necrosis.

The half-life of lidocaine ranges from 1.5 to 2 hours. It exhibits a rapid onset of action within a few minutes and has a duration of action of 30 to 60 minutes when used alone. However, when co-administered with adrenaline, its duration of action is prolonged. It is worth mentioning that lidocaine tends to induce vasodilation, primarily attributed to the inhibition of action potentials in vasoconstrictor sympathetic nerves through the blocking of sodium channels.

A patient with central vertigo would typically show a normal head impulse test result, indicating a normal vestibulo-ocular reflex. However, they would likely have an abnormal alternate cover test result, with a slight vertical correction, suggesting a central lesion like a stroke. A positive Romberg’s test can identify instability related to vertigo but cannot differentiate between peripheral and central causes. On the other hand, a positive Unterberger’s test indicates labyrinth dysfunction but does not indicate a central cause.

Further Reading:

Vertigo is a symptom characterized by a false sensation of movement, such as spinning or rotation, in the absence of any actual physical movement. It is not a diagnosis itself, but rather a description of the sensation experienced by the individual. Dizziness, on the other hand, refers to a perception of disturbed or impaired spatial orientation without a false sense of motion.

Vertigo can be classified as either peripheral or central. Peripheral vertigo is more common and is caused by problems in the inner ear that affect the labyrinth or vestibular nerve. Examples of peripheral vertigo include BPPV, vestibular neuritis, labyrinthitis, and Meniere’s disease. Central vertigo, on the other hand, is caused by pathology in the brain, such as in the brainstem or cerebellum. Examples of central vertigo include migraine, TIA and stroke, cerebellar tumor, acoustic neuroma, and multiple sclerosis.

There are certain features that can help differentiate between peripheral and central vertigo. Peripheral vertigo is often associated with severe nausea and vomiting, hearing loss or tinnitus, and a positive head impulse test. Central vertigo may be characterized by prolonged and severe vertigo, new-onset headache, recent trauma, cardiovascular risk factors, inability to stand or walk with eyes open, focal neurological deficit, and a negative head impulse test.

Nystagmus, an involuntary eye movement, can also provide clues about the underlying cause of vertigo. Central causes of vertigo often have nystagmus that is direction-changing on lateral gaze, purely vertical or torsional, not suppressed by visual fixation, non-fatigable, and commonly large amplitude. Peripheral causes of vertigo often have horizontal nystagmus with a torsional component that does not change direction with gaze, disappears with fixation of the gaze, and may have large amplitude early in the course of Meniere’s disease or vestibular neuritis.

There are various causes of vertigo, including viral labyrinthitis, vestibular neuritis, benign paroxysmal positional vertigo, Meniere’s disease, vertebrobasilar ischemia, and acoustic neuroma. Each of these disorders has its own unique characteristics and may be associated with other symptoms such as hearing loss, tinnitus, or neurological deficits.

When assessing a patient with vertigo, it is important to perform a cardiovascular and neurological examination, including assessing cranial nerves, cerebellar signs, eye movements, gait, coordination, and evidence of peripheral neuropathy.

The most suitable dosage of epinephrine for a patient experiencing anaphylaxis after a flu vaccination is 500 micrograms (0.5ml 1 in 1,000) adrenaline by intramuscular injection.

Anaphylaxis is a severe and life-threatening hypersensitivity reaction that can have sudden onset and progression. It is characterized by skin or mucosal changes and can lead to life-threatening airway, breathing, or circulatory problems. Anaphylaxis can be allergic or non-allergic in nature.

In allergic anaphylaxis, there is an immediate hypersensitivity reaction where an antigen stimulates the production of IgE antibodies. These antibodies bind to mast cells and basophils. Upon re-exposure to the antigen, the IgE-covered cells release histamine and other inflammatory mediators, causing smooth muscle contraction and vasodilation.

Non-allergic anaphylaxis occurs when mast cells degrade due to a non-immune mediator. The clinical outcome is the same as in allergic anaphylaxis.

The management of anaphylaxis is the same regardless of the cause. Adrenaline is the most important drug and should be administered as soon as possible. The recommended doses for adrenaline vary based on age. Other treatments include high flow oxygen and an IV fluid challenge. Corticosteroids and chlorpheniramine are no longer recommended, while non-sedating antihistamines may be considered as third-line treatment after initial stabilization of airway, breathing, and circulation.

Common causes of anaphylaxis include food (such as nuts, which is the most common cause in children), drugs, and venom (such as wasp stings). Sometimes it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.

The Resuscitation Council (UK) provides guidelines for the management of anaphylaxis, including a visual algorithm that outlines the recommended steps for treatment.
https://www.resus.org.uk/sites/default/files/2021-05/Emergency%20Treatment%20of%20Anaphylaxis%20May%202021_0.pdf

This patient is likely to have pigeon fancier’s lung, which is a type of extrinsic allergic alveolitis (EAA) caused by chronic exposure to avian antigens found in bird droppings. This condition leads to hypersensitivity pneumonitis and the formation of granulomas in the lungs.

While his presentation could also be consistent with idiopathic pulmonary fibrosis, the fact that he keeps and races pigeons makes EAA more likely in this case.

EAA can manifest as either an acute or chronic condition. The acute form typically presents with flu-like symptoms such as fever, cough, chest tightness, and breathlessness occurring 4 to 6 hours after exposure.

The clinical features of chronic pigeon fancier’s lung include a productive cough, progressive breathlessness, weight loss, anorexia, fatigue, and malaise.

Other forms of EAA include farmer’s lung (caused by exposure to Saccharopolyspora rectivirgula from wet hay), malt-worker’s lung (caused by exposure to Aspergillus clavatus from moldy malt), cheese-worker’s lung (caused by exposure to Penicillium casei from moldy cheese), chemical worker’s lung (caused by exposure to trimetallic anhydride, diisocyanate, and methylene diisocyanate), mushroom worker’s lung (caused by exposure to thermophilic actinomycetes in mushroom compost), and hot tub lung (caused by exposure to Mycobacterium avium from poorly maintained hot tubs).

The subtraction of serial 7s is included in the 30-point Folstein mini-mental state examination (MMSE), but it is not included in the AMTS. The AMTS consists of ten questions that assess various cognitive abilities. These questions include asking about age, the nearest hour, the current year, the name of the hospital or location, the ability to recognize two people, date of birth, knowledge of historical events, knowledge of the present monarch or prime minister, counting backwards from 20 to 1, and recalling an address given earlier in the test.

Osteoporosis and fragility fractures are more likely to occur in individuals with low levels of estrogen. Menopause, which causes a decrease in estrogen, can lead to estrogen deficiency. Estrogen plays a role in preventing bone breakdown by inhibiting osteoclast activity. After menopause, there is an increase in osteoclast activity, resulting in a rapid decline in bone mineral density. Osteoporosis is also associated with the long-term use of corticosteroids.

Further Reading:

Fragility fractures are fractures that occur following a fall from standing height or less, and may be atraumatic. They often occur in the presence of osteoporosis, a disease characterized by low bone mass and structural deterioration of bone tissue. Fragility fractures commonly affect the wrist, spine, hip, and arm.

Osteoporosis is defined as a bone mineral density (BMD) of 2.5 standard deviations below the mean peak mass, as measured by dual-energy X-ray absorptiometry (DXA). Osteopenia, on the other hand, refers to low bone mass between normal bone mass and osteoporosis, with a T-score between -1 to -2.5.

The pathophysiology of osteoporosis involves increased osteoclast activity relative to bone production by osteoblasts. The prevalence of osteoporosis increases with age, from approximately 2% at 50 years to almost 50% at 80 years.

There are various risk factors for fragility fractures, including endocrine diseases, GI causes of malabsorption, chronic kidney and liver diseases, menopause, immobility, low body mass index, advancing age, oral corticosteroids, smoking, alcohol consumption, previous fragility fractures, rheumatological conditions, parental history of hip fracture, certain medications, visual impairment, neuromuscular weakness, cognitive impairment, and unsafe home environment.

Assessment of a patient with a possible fragility fracture should include evaluating the risk of further falls, the risk of osteoporosis, excluding secondary causes of osteoporosis, and ruling out non-osteoporotic causes for fragility fractures such as metastatic bone disease, multiple myeloma, osteomalacia, and Paget’s disease.

Management of fragility fractures involves initial management by the emergency clinician, while treatment of low bone density is often delegated to the medical team or general practitioner. Management considerations include determining who needs formal risk assessment, who needs a DXA scan to measure BMD, providing lifestyle advice, and deciding who requires drug treatment.

Medication for osteoporosis typically includes vitamin D, calcium, and bisphosphonates. Vitamin D and calcium supplementation should be considered based on individual needs, while bisphosphonates are advised for postmenopausal women and men over 50 years with confirmed osteoporosis or those taking high doses of oral corticosteroids.

The initial symptoms of ARS usually include feelings of nausea and the urge to vomit. During the prodromal stage, individuals may also experience a loss of appetite and, in some cases, diarrhea, which can vary depending on the amount of exposure. These symptoms can manifest within minutes to days after being exposed to ARS.

Further Reading:

Radiation exposure refers to the emission or transmission of energy in the form of waves or particles through space or a material medium. There are two types of radiation: ionizing and non-ionizing. Non-ionizing radiation, such as radio waves and visible light, has enough energy to move atoms within a molecule but not enough to remove electrons from atoms. Ionizing radiation, on the other hand, has enough energy to ionize atoms or molecules by detaching electrons from them.

There are different types of ionizing radiation, including alpha particles, beta particles, gamma rays, and X-rays. Alpha particles are positively charged and consist of 2 protons and 2 neutrons from the atom’s nucleus. They are emitted from the decay of heavy radioactive elements and do not travel far from the source atom. Beta particles are small, fast-moving particles with a negative electrical charge that are emitted from an atom’s nucleus during radioactive decay. They are more penetrating than alpha particles but less damaging to living tissue. Gamma rays and X-rays are weightless packets of energy called photons. Gamma rays are often emitted along with alpha or beta particles during radioactive decay and can easily penetrate barriers. X-rays, on the other hand, are generally lower in energy and less penetrating than gamma rays.

Exposure to ionizing radiation can damage tissue cells by dislodging orbital electrons, leading to the generation of highly reactive ion pairs. This can result in DNA damage and an increased risk of future malignant change. The extent of cell damage depends on factors such as the type of radiation, time duration of exposure, distance from the source, and extent of shielding.

The absorbed dose of radiation is directly proportional to time, so it is important to minimize the amount of time spent in the vicinity of a radioactive source. A lethal dose of radiation without medical management is 4.5 sieverts (Sv) to kill 50% of the population at 60 days. With medical management, the lethal dose is 5-6 Sv. The immediate effects of ionizing radiation can range from radiation burns to radiation sickness, which is divided into three main syndromes: hematopoietic, gastrointestinal, and neurovascular. Long-term effects can include hematopoietic cancers and solid tumor formation.

In terms of management, support is mainly supportive and includes IV fluids, antiemetics, analgesia, nutritional support, antibiotics, blood component substitution, and reduction of brain edema.

Wernicke’s encephalopathy is a condition that is linked to alcohol abuse and other causes of thiamine deficiency. It is commonly identified by the presence of three main symptoms: acute confusion, ophthalmoplegia (paralysis or weakness of the eye muscles), and ataxia (loss of coordination). Additional signs may include papilloedema (swelling of the optic disc), hearing loss, apathy, dysphagia (difficulty swallowing), memory impairment, and hypothermia. Most cases also involve peripheral neuropathy, primarily affecting the legs.

This condition is characterized by the occurrence of acute capillary hemorrhages, astrocytosis (abnormal increase in astrocytes, a type of brain cell), and neuronal death in the upper brainstem and diencephalon. These abnormalities can be detected through MRI scanning, while CT scanning is not very useful for diagnosis.

If left untreated, most patients with Wernicke’s encephalopathy will develop a condition known as Korsakoff psychosis. This condition is characterized by retrograde amnesia (loss of memory for events that occurred before the onset of amnesia), an inability to form new memories, disordered perception of time, and confabulation (fabrication of false memories).

When Wernicke’s encephalopathy is suspected, it is crucial to administer parenteral thiamine (such as Pabrinex) for at least 5 days. Following the parenteral therapy, oral thiamine should be continued.

Wolff-Parkinson-White (WPW) syndrome is a condition that affects the electrical system of the heart. It occurs when there is an abnormal pathway, known as the bundle of Kent, between the atria and the ventricles. This pathway can cause premature contractions of the ventricles, leading to a type of rapid heartbeat called atrioventricular re-entrant tachycardia (AVRT).

In a normal heart rhythm, the electrical signals travel through the bundle of Kent and stimulate the ventricles. However, in WPW syndrome, these signals can cause the ventricles to contract prematurely. This can be seen on an electrocardiogram (ECG) as a shortened PR interval, a slurring of the initial rise in the QRS complex (known as a delta wave), and a widening of the QRS complex.

There are two distinct types of WPW syndrome that can be identified on an ECG. Type A is characterized by predominantly positive delta waves and QRS complexes in the praecordial leads, with a dominant R wave in V1. This can sometimes be mistaken for right bundle branch block (RBBB). Type B, on the other hand, shows predominantly negative delta waves and QRS complexes in leads V1 and V2, and positive in the other praecordial leads, resembling left bundle branch block (LBBB).

Overall, WPW syndrome is a condition that affects the electrical conduction system of the heart, leading to abnormal heart rhythms. It can be identified on an ECG by specific features such as shortened PR interval, delta waves, and widened QRS complex.

Mandibular fractures are quite common, especially among young men. The most common cause of these fractures is assault, but they can also occur due to sporting injuries, motor vehicle accidents, and falls. The mandible and skull together form a complete bony ring, with the only interruption being the temporomandibular joints (TMJs). While it is expected that mandibular fractures would occur in two places, sometimes they only occur in one location. The most frequently affected areas are the angle of the mandible (27%), mandibular symphysis (21%), mandibular condylar and subcondylar (18%), body of the mandible (15%), ramus of the mandible (5%), coronoid process (1-3%), and alveolar ridge (2%).

Diabetes insipidus is characterized by low urine osmolality and high serum osmolality. This occurs because the kidneys are unable to properly reabsorb water and sodium, resulting in diluted urine with low osmolality. On the other hand, the loss of water and sodium leads to dehydration and concentration of the serum, causing a rise in serum osmolality. Hypernatremia is a common finding in patients with diabetes insipidus. In cases of nephrogenic diabetes insipidus, hypokalemia and hypercalcemia may also be observed. Glucose levels are typically normal, unless the patient also has diabetes mellitus.

Further Reading:

Diabetes insipidus (DI) is a condition characterized by either a decrease in the secretion of antidiuretic hormone (cranial DI) or insensitivity to antidiuretic hormone (nephrogenic DI). Antidiuretic hormone, also known as arginine vasopressin, is produced in the hypothalamus and released from the posterior pituitary. The typical biochemical disturbances seen in DI include elevated plasma osmolality, low urine osmolality, polyuria, and hypernatraemia.

Cranial DI can be caused by various factors such as head injury, CNS infections, pituitary tumors, and pituitary surgery. Nephrogenic DI, on the other hand, can be genetic or result from electrolyte disturbances or the use of certain drugs. Symptoms of DI include polyuria, polydipsia, nocturia, signs of dehydration, and in children, irritability, failure to thrive, and fatigue.

To diagnose DI, a 24-hour urine collection is done to confirm polyuria, and U&Es will typically show hypernatraemia. High plasma osmolality with low urine osmolality is also observed. Imaging studies such as MRI of the pituitary, hypothalamus, and surrounding tissues may be done, as well as a fluid deprivation test to evaluate the response to desmopressin.

Management of cranial DI involves supplementation with desmopressin, a synthetic form of arginine vasopressin. However, hyponatraemia is a common side effect that needs to be monitored. In nephrogenic DI, desmopressin supplementation is usually not effective, and management focuses on ensuring adequate fluid intake to offset water loss and monitoring electrolyte levels. Causative drugs need to be stopped, and there is a risk of developing complications such as hydroureteronephrosis and an overdistended bladder.

Febrile convulsions are harmless, generalized seizures that occur in otherwise healthy children who have a fever due to an infection outside the brain. To diagnose febrile convulsions, the child must be developing normally, the seizure should last less than 20 minutes, have no complex features, and not cause any lasting abnormalities.

The prognosis for febrile convulsions is generally positive. There is a 30 to 50% chance of experiencing recurrent febrile convulsions, with a 10% risk of recurrence within the first 24 hours. The likelihood of developing long-term epilepsy is around 6%.

Complex febrile convulsions are characterized by certain factors. These include focal seizures, seizures lasting longer than 15 minutes, experiencing more than one convulsion during a single fever episode, or the child being left with a focal neurological deficit.

Overall, febrile convulsions are typically harmless and do not cause any lasting damage.