The hypoglossal canal is the pathway for the hypoglossal nerve.

Foramina of the Base of the Skull

The base of the skull contains several openings called foramina, which allow for the passage of nerves, blood vessels, and other structures. The foramen ovale, located in the sphenoid bone, contains the mandibular nerve, otic ganglion, accessory meningeal artery, and emissary veins. The foramen spinosum, also in the sphenoid bone, contains the middle meningeal artery and meningeal branch of the mandibular nerve. The foramen rotundum, also in the sphenoid bone, contains the maxillary nerve.

The foramen lacerum, located in the sphenoid bone, is initially occluded by a cartilaginous plug and contains the internal carotid artery, nerve and artery of the pterygoid canal, and the base of the medial pterygoid plate. The jugular foramen, located in the temporal bone, contains the inferior petrosal sinus, glossopharyngeal, vagus, and accessory nerves, sigmoid sinus, and meningeal branches from the occipital and ascending pharyngeal arteries.

The foramen magnum, located in the occipital bone, contains the anterior and posterior spinal arteries, vertebral arteries, and medulla oblongata. The stylomastoid foramen, located in the temporal bone, contains the stylomastoid artery and facial nerve. Finally, the superior orbital fissure, located in the sphenoid bone, contains the oculomotor nerve, recurrent meningeal artery, trochlear nerve, lacrimal, frontal, and nasociliary branches of the ophthalmic nerve, and abducent nerve.

Visual Hallucinations in Organic Psychosis

Visual hallucinations are a common occurrence in organic psychosis, particularly in cases of delirium. These hallucinations often take the form of animals and people. In cases of alcoholic delirium, the visual hallucinations tend to be small objects such as spider webs or hairs, which appear against a clear background like a white wall.

It is important to note that the psychotic experiences associated with delirium tremens can be mistaken for other psychotic illnesses like schizophrenia or mania. However, delirium is a medical emergency that requires immediate medical attention. Admission to a psychiatric hospital may not be the best course of action due to a lack of trained staff in emergency medicine.

In summary, visual hallucinations are a common symptom of organic psychosis, particularly in cases of delirium. These hallucinations can take many forms, including animals, people, and small objects. It is important to seek medical attention immediately if experiencing these symptoms, as delirium is a medical emergency that requires prompt treatment.

The correct medium for culturing Escherichia coli and obtaining pink colonies is MacConkey agar. This is because E. coli is a lactose-fermenting bacteria, and MacConkey’s agar contains lactose that is utilized by such bacteria to produce acid, resulting in the formation of pink colonies. Charcoal-yeast agar, chocolate agar, and Lowenstein-Jensen agar are not appropriate for culturing E. coli as they are used for isolating other bacteria that cause different illnesses.

Culture Requirements for Common Organisms

Different microorganisms require specific culture conditions to grow and thrive. The table above lists some of the culture requirements for the more common organisms. For instance, Neisseria gonorrhoeae requires Thayer-Martin agar, which is a variant of chocolate agar, and the addition of Vancomycin, Polymyxin, and Nystatin to inhibit Gram-positive, Gram-negative, and fungal growth, respectively. Haemophilus influenzae, on the other hand, grows on chocolate agar with factors V (NAD+) and X (hematin).

To remember the culture requirements for some of these organisms, some mnemonics can be used. For example, Nice Homes have chocolate can help recall that Neisseria and Haemophilus grow on chocolate agar. If I Tell-U the Corny joke Right, you’ll Laugh can be used to remember that Corynebacterium diphtheriae grows on tellurite agar or Loeffler’s media. Lactating pink monkeys can help recall that lactose fermenting bacteria, such as Escherichia coli, grow on MacConkey agar resulting in pink colonies. Finally, BORDETella pertussis can be used to remember that Bordetella pertussis grows on Bordet-Gengou (potato) agar.

The left gonadal veins empty into the left renal vein, meaning that any thrombus originating from the left gonadal veins would travel to the left renal vein. However, if the thrombus originated from the right gonadal vein, it would flow into the inferior vena cava (IVC) since the right gonadal vein directly drains into the IVC.

The portal vein is typically formed by the merging of the superior mesenteric and splenic veins, and it also receives blood from the inferior mesenteric, gastric, and cystic veins.

The superior vena cava collects venous drainage from the upper half of the body, specifically above the diaphragm.

Anatomy of the Inferior Vena Cava

The inferior vena cava (IVC) originates from the fifth lumbar vertebrae and is formed by the merging of the left and right common iliac veins. It passes to the right of the midline and receives drainage from paired segmental lumbar veins throughout its length. The right gonadal vein empties directly into the cava, while the left gonadal vein usually empties into the left renal vein. The renal veins and hepatic veins are the next major veins that drain into the IVC. The IVC pierces the central tendon of the diaphragm at the level of T8 and empties into the right atrium of the heart.

The IVC is related anteriorly to the small bowel, the first and third parts of the duodenum, the head of the pancreas, the liver and bile duct, the right common iliac artery, and the right gonadal artery. Posteriorly, it is related to the right renal artery, the right psoas muscle, the right sympathetic chain, and the coeliac ganglion.

The IVC is divided into different levels based on the veins that drain into it. At the level of T8, it receives drainage from the hepatic vein and inferior phrenic vein before piercing the diaphragm. At the level of L1, it receives drainage from the suprarenal veins and renal vein. At the level of L2, it receives drainage from the gonadal vein, and at the level of L1-5, it receives drainage from the lumbar veins. Finally, at the level of L5, the common iliac vein merges to form the IVC.

The most frequent breast lumps in women aged 15-25 are fibroadenomas. These lumps are usually firm, mobile, and less than 3 cm in size. They are not a cause for concern and typically disappear within a few years.

Fat necrosis is a condition that occurs after breast trauma, such as a sports injury or core needle biopsy. The affected area may be tender and show bruising. However, it usually resolves on its own and is unlikely to persist for an extended period.

Overview of Benign Breast Lesions

Benign breast lesions are non-cancerous growths that can occur in the breast tissue. There are several types of benign breast lesions, each with their own unique features and treatment options.

Fibroadenomas are one of the most common types of benign breast lesions, accounting for 12% of all breast masses. They develop from a whole lobule and are typically mobile, firm breast lumps. While they do not increase the risk of malignancy, surgical excision is usually recommended if the lesion is larger than 3 cm. Phyllodes tumors, a rare type of fibroadenoma, should be widely excised or removed with a mastectomy if the lesion is large.

Breast cysts are another common type of benign breast lesion, with 7% of all Western females presenting with one. They usually present as a smooth, discrete lump and may be aspirated. However, if the cyst is blood-stained or persistently refills, it should be biopsied or excised.

Sclerosing adenosis, radial scars, and complex sclerosing lesions can cause mammographic changes that mimic carcinoma. However, they are considered a disorder of involution and do not increase the risk of malignancy. Biopsy is recommended, but excision is not mandatory.

Epithelial hyperplasia is a disorder that consists of increased cellularity of the terminal lobular unit, and atypical features may be present. Those with atypical features and a family history of breast cancer have a greatly increased risk of malignancy and may require surgical resection.

Fat necrosis can occur in up to 40% of cases and usually has a traumatic cause. Physical features may mimic carcinoma, but imaging and core biopsy can help diagnose the lesion.

Duct papillomas usually present with nipple discharge and may require microdochectomy if they are large. However, they do not increase the risk of malignancy.

Overall, benign breast lesions can have varying presentations and treatment options. It is important to consult with a healthcare provider to determine the best course of action for each individual case.

B cells have the ability to act as an antigen presenting cell. One of their functions is to present antigen through MHC II to Helper T cells. CD40L found on Helper T cells interacts with CD40 on B cells. Toll-like receptors found on T cells interact with MHC molecules. IL-2 secreted by Helper T cells interacts with B cells, stimulating them to become plasma cells and memory cells. MHC I molecules interact with cytotoxic T cells.

The adaptive immune response involves several types of cells, including helper T cells, cytotoxic T cells, B cells, and plasma cells. Helper T cells are responsible for the cell-mediated immune response and recognize antigens presented by MHC class II molecules. They express CD4, CD3, TCR, and CD28 and are a major source of IL-2. Cytotoxic T cells also participate in the cell-mediated immune response and recognize antigens presented by MHC class I molecules. They induce apoptosis in virally infected and tumor cells and express CD8 and CD3. Both helper T cells and cytotoxic T cells mediate acute and chronic organ rejection.

B cells are the primary cells of the humoral immune response and act as antigen-presenting cells. They also mediate hyperacute organ rejection. Plasma cells are differentiated from B cells and produce large amounts of antibody specific to a particular antigen. Overall, these cells work together to mount a targeted and specific immune response to invading pathogens or abnormal cells.

Hodgkin’s disease is characterized by the presence of Reed Sternberg cells, while sarcoid is associated with the presence of all other cell types.

Chronic inflammation can occur as a result of acute inflammation or as a primary process. There are three main processes that can lead to chronic inflammation: persisting infection with certain organisms, prolonged exposure to non-biodegradable substances, and autoimmune conditions involving antibodies formed against host antigens. Acute inflammation involves changes to existing vascular structure and increased permeability of endothelial cells, as well as infiltration of neutrophils. In contrast, chronic inflammation is characterized by angiogenesis and the predominance of macrophages, plasma cells, and lymphocytes. The process may resolve with suppuration, complete resolution, abscess formation, or progression to chronic inflammation. Healing by fibrosis is the main result of chronic inflammation. Granulomas, which consist of a microscopic aggregation of macrophages, are pathognomonic of chronic inflammation and can be found in conditions such as colonic Crohn’s disease. Growth factors released by activated macrophages, such as interferon and fibroblast growth factor, may have systemic features resulting in systemic symptoms and signs in individuals with long-standing chronic inflammation.

Sterile pyuria can be caused by urethritis as a result of a sexually transmitted disease such as chlamydia.

Understanding Sterile Pyuria and Its Causes

Sterile pyuria is a medical condition characterized by the presence of white blood cells in the urine without any bacterial growth. It is a common finding in patients with urinary tract infections (UTIs) but can also be caused by other underlying conditions.

Some of the common causes of sterile pyuria include partially treated UTIs, urethritis (such as Chlamydia), renal tuberculosis, renal stones, appendicitis, bladder or renal cell cancer, adult polycystic kidney disease, and analgesic nephropathy.

It is important to identify the underlying cause of sterile pyuria to ensure proper treatment and prevent complications. Patients with this condition should seek medical attention and undergo further evaluation to determine the root cause of their symptoms. Early detection and treatment can help prevent further damage to the urinary tract and improve overall health outcomes.

The ankle reflex is a neurological test that assesses the function of the S1 and S2 nerve roots. When the Achilles tendon is tapped with a reflex hammer, the resulting contraction of the calf muscle indicates the integrity of these nerve roots. A normal response is a quick and brisk contraction of the muscle, while a diminished or absent response may indicate nerve damage or dysfunction. The ankle reflex is a simple and non-invasive test that can provide valuable information about a patient’s neurological health.

The ankle reflex is a test that checks the function of the S1 and S2 nerve roots by tapping the Achilles tendon with a tendon hammer. This reflex is often delayed in individuals with L5 and S1 disk prolapses.

The patient had auditory hallucinations and a delusion that he was being spied on for 6 months, indicating a diagnosis of schizophrenia. The psychiatrist likely prescribed an antipsychotic, which can cause prolonged QT interval and require electrocardiograms. Galactorrhea, a common side effect of antipsychotics like risperidone, olanzapine, or quetiapine, occurs because the medication inhibits dopamine, which usually suppresses prolactin release. The patient did not initially report symptoms of a prolactinoma and was correctly diagnosed with schizophrenia. The relief of dopamine inhibition on prolactin release is the cause of antipsychotic-induced galactorrhea. While schizophrenia patients may develop endocrine disorders, this is not the best explanation for a patient experiencing known side effects of medication. If galactorrhea persists or worsens after stopping the medication, referral to an endocrinologist may be necessary. The patient’s well-controlled condition and the presence of galactorrhea indicate a medication side effect, and worsening would manifest as an increase in positive or negative symptoms.

Antipsychotics are a type of medication used to treat schizophrenia, psychosis, mania, and agitation. They are divided into two categories: typical and atypical antipsychotics. The latter were developed to address the extrapyramidal side-effects associated with the first generation of typical antipsychotics. Typical antipsychotics work by blocking dopaminergic transmission in the mesolimbic pathways through dopamine D2 receptor antagonism. However, they are known to cause extrapyramidal side-effects such as Parkinsonism, acute dystonia, akathisia, and tardive dyskinesia. These side-effects can be managed with procyclidine. Other side-effects of typical antipsychotics include antimuscarinic effects, sedation, weight gain, raised prolactin, impaired glucose tolerance, neuroleptic malignant syndrome, reduced seizure threshold, and prolonged QT interval. The Medicines and Healthcare products Regulatory Agency has issued specific warnings when antipsychotics are used in elderly patients due to an increased risk of stroke and venous thromboembolism.

The upper limb has both superficial and deep veins. Among the superficial veins are the cephalic, basilic, and median cubital veins. The median cubital vein, which connects the cephalic and basilic veins, is situated in the antecubital fossa and is the preferred site for venepuncture because it is easy to locate and access. However, deep veins like the brachial, ulnar, and radial veins are not suitable for venepuncture as they are located beneath the deep fascia.

The Cephalic Vein: Path and Connections

The cephalic vein is a major blood vessel that runs along the lateral side of the arm. It begins at the dorsal venous arch, which drains blood from the hand and wrist, and travels up the arm, crossing the anatomical snuffbox. At the antecubital fossa, the cephalic vein is connected to the basilic vein by the median cubital vein. This connection is commonly used for blood draws and IV insertions.

After passing through the antecubital fossa, the cephalic vein continues up the arm and pierces the deep fascia of the deltopectoral groove to join the axillary vein. This junction is located near the shoulder and marks the end of the cephalic vein’s path.

Overall, the cephalic vein plays an important role in the circulation of blood in the upper limb. Its connections to other major veins in the arm make it a valuable site for medical procedures, while its path through the deltopectoral groove allows it to contribute to the larger network of veins that drain blood from the upper body.

The mesoderm is responsible for the development of connective tissue and muscles.

Embryological Layers and Their Derivatives

Embryonic development involves the formation of three primary germ layers: ectoderm, mesoderm, and endoderm. Each layer gives rise to specific tissues and organs in the developing embryo. The ectoderm forms the surface ectoderm, which gives rise to the epidermis, mammary glands, and lens of the eye, as well as the neural tube, which gives rise to the central nervous system (CNS) and associated structures such as the posterior pituitary and retina. The neural crest, which arises from the neural tube, gives rise to a variety of structures including autonomic nerves, cranial nerves, facial and skull bones, and adrenal cortex. The mesoderm gives rise to connective tissue, muscle, bones (except facial and skull), and organs such as the kidneys, ureters, gonads, and spleen. The endoderm gives rise to the epithelial lining of the gastrointestinal tract, liver, pancreas, thyroid, parathyroid, and thymus.

The area between Z lines is known as the sarcomere. The skeletal muscle is composed of the following elements, as shown in the diagram.

The Process of Muscle Contraction

Muscle contraction is a complex process that involves several steps. It begins with an action potential reaching the neuromuscular junction, which causes a calcium ion influx through voltage-gated calcium channels. This influx leads to the release of acetylcholine into the extracellular space, which activates nicotinic acetylcholine receptors, triggering an action potential. The action potential then spreads through the T-tubules, activating L-type voltage-dependent calcium channels in the T-tubule membrane, which are close to calcium-release channels in the adjacent sarcoplasmic reticulum. This causes the sarcoplasmic reticulum to release calcium, which binds to troponin C, causing a conformational change that allows tropomyosin to move, unblocking the binding sites. Myosin then binds to the newly released binding site, releasing ADP and pulling the Z bands towards each other. ATP binds to myosin, releasing actin.

The components involved in muscle contraction include the sarcomere, which is the basic unit of muscles that gives skeletal and cardiac muscles their striated appearance. The I-band is the zone of thin filaments that is not superimposed by thick filaments, while the A-band contains the entire length of a single thick filament. The H-zone is the zone of the thick filaments that is not superimposed by the thin filaments, and the M-line is in the middle of the sarcomere, cross-linking myosin. The sarcoplasmic reticulum releases calcium ion in response to depolarization, while actin is the thin filaments that transmit the forces generated by myosin to the ends of the muscle. Myosin is the thick filaments that bind to the thin filament, while titin connects the Z-line to the thick filament, altering the structure of tropomyosin. Tropomyosin covers the myosin-binding sites on actin, while troponin-C binds with calcium ions. The T-tubule is an invagination of the sarcoplasmic reticulum that helps co-ordinate muscular contraction.

There are two types of skeletal muscle fibres: type I and type II. Type I fibres have a slow contraction time, are red in colour due to the presence of myoglobin, and are used for sustained force. They have a high mitochondrial density and use triglycerides as

Sources of Vitamin D

Vitamin D is a crucial nutrient that is primarily produced by the body when exposed to sunlight. However, in the absence of sunlight, it is important to obtain vitamin D from dietary sources. These sources include oily fish such as salmon, mackerel, and catfish, as well as meat, eggs, and some mushrooms. It is important to note that vitamin D-containing foods are mostly animal or fish-based, which may put strict vegetarians at a greater risk of deficiency.

Vitamin D exists in two forms, D2 and D3, with dietary sources containing vitamin D3 in greater abundance than D2. It is essential to ensure that the body receives an adequate amount of vitamin D, as it plays a crucial role in maintaining bone health, regulating the immune system, and reducing the risk of certain diseases. By incorporating vitamin D-rich foods into the diet, individuals can ensure that they are meeting their daily requirements for this important nutrient.

The expiratory reserve volume refers to the maximum amount of air that can be exhaled after a normal breath out. It is important to note that this volume can be reduced in conditions that limit lung expansion, such as obesity and ascites. Obesity, in particular, can cause a restrictive pattern on spirometry, where the FEV1/FVC ratio is ≥0.8. Other restrictive lung conditions include idiopathic pulmonary fibrosis, pleural effusion, ascites, and neuromuscular disorders that limit chest expansion. On the other hand, obstructive disorders like asthma and COPD lead to a FEV1/FVC ratio of <0.7, limiting the amount of air that can be exhaled in one second. It is essential to understand the different lung volumes and capacities, including inspiratory reserve volume, tidal volume, expiratory reserve volume, residual volume, inspiratory capacity, vital capacity, functional residual capacity, and total lung capacity. Understanding Lung Volumes in Respiratory Physiology In respiratory physiology, lung volumes can be measured to determine the amount of air that moves in and out of the lungs during breathing. The diagram above shows the different lung volumes that can be measured. Tidal volume (TV) refers to the amount of air that is inspired or expired with each breath at rest. In males, the TV is 500ml while in females, it is 350ml. Inspiratory reserve volume (IRV) is the maximum volume of air that can be inspired at the end of a normal tidal inspiration. The inspiratory capacity is the sum of TV and IRV. On the other hand, expiratory reserve volume (ERV) is the maximum volume of air that can be expired at the end of a normal tidal expiration. Residual volume (RV) is the volume of air that remains in the lungs after maximal expiration. It increases with age and can be calculated by subtracting ERV from FRC. Speaking of FRC, it is the volume in the lungs at the end-expiratory position and is equal to the sum of ERV and RV. Vital capacity (VC) is the maximum volume of air that can be expired after a maximal inspiration. It decreases with age and can be calculated by adding inspiratory capacity and ERV. Lastly, total lung capacity (TLC) is the sum of vital capacity and residual volume. Physiological dead space (VD) is calculated by multiplying tidal volume by the difference between arterial carbon dioxide pressure (PaCO2) and end-tidal carbon dioxide pressure (PeCO2) and then dividing the result by PaCO2.

The lesser trochanter is the insertion point of the psoas major.

The Psoas Muscle: Origin, Insertion, Innervation, and Action

The psoas muscle is a deep-seated muscle that originates from the transverse processes of the five lumbar vertebrae and the superficial part originates from T12 and the first four lumbar vertebrae. It inserts into the lesser trochanter of the femur and is innervated by the anterior rami of L1 to L3.

The main action of the psoas muscle is flexion and external rotation of the hip. When both sides of the muscle contract, it can raise the trunk from the supine position. The psoas muscle is an important muscle for maintaining proper posture and movement, and it is often targeted in exercises such as lunges and leg lifts.

Hypotension, particularly on the first dose, and deterioration of renal function are common side effects of ACE inhibitors in patients. Although angioedema is a rare side effect of ACE inhibitors, oedema is typically associated with calcium channel blockers. Diuretics may cause excessive urine output, while shortness of breath and headaches are uncommon.

Angiotensin-converting enzyme (ACE) inhibitors are commonly used as the first-line treatment for hypertension and heart failure in younger patients. However, they may not be as effective in treating hypertensive Afro-Caribbean patients. ACE inhibitors are also used to treat diabetic nephropathy and prevent ischaemic heart disease. These drugs work by inhibiting the conversion of angiotensin I to angiotensin II and are metabolized in the liver.

While ACE inhibitors are generally well-tolerated, they can cause side effects such as cough, angioedema, hyperkalaemia, and first-dose hypotension. Patients with certain conditions, such as renovascular disease, aortic stenosis, or hereditary or idiopathic angioedema, should use ACE inhibitors with caution or avoid them altogether. Pregnant and breastfeeding women should also avoid these drugs.

Patients taking high-dose diuretics may be at increased risk of hypotension when using ACE inhibitors. Therefore, it is important to monitor urea and electrolyte levels before and after starting treatment, as well as any changes in creatinine and potassium levels. Acceptable changes include a 30% increase in serum creatinine from baseline and an increase in potassium up to 5.5 mmol/l. Patients with undiagnosed bilateral renal artery stenosis may experience significant renal impairment when using ACE inhibitors.

The current NICE guidelines recommend using a flow chart to manage hypertension, with ACE inhibitors as the first-line treatment for patients under 55 years old. However, individual patient factors and comorbidities should be taken into account when deciding on the best treatment plan.

Haptoglobin plays a crucial role in binding free haemoglobin following haemolysis. This binding forms a complex that can be cleared and metabolized by macrophages through CD163 receptors. This process is essential in preventing local toxicity from haemoglobin degradation products, such as free radicals. Therefore, reduced haptoglobin levels upon testing can indicate intravascular haemolysis. It is important to note that haemopexin binds free haem, not haemoglobin itself, and haptoglobin does not bind complexed haemoglobin or free heme.

Understanding Haemolytic Anaemias by Site

Haemolytic anaemias can be classified by the site of haemolysis, either intravascular or extravascular. In intravascular haemolysis, free haemoglobin is released and binds to haptoglobin. As haptoglobin becomes saturated, haemoglobin binds to albumin forming methaemalbumin, which can be detected by Schumm’s test. Free haemoglobin is then excreted in the urine as haemoglobinuria and haemosiderinuria. Causes of intravascular haemolysis include mismatched blood transfusion, red cell fragmentation due to heart valves, TTP, DIC, HUS, paroxysmal nocturnal haemoglobinuria, and cold autoimmune haemolytic anaemia.

On the other hand, extravascular haemolysis occurs when red blood cells are destroyed by macrophages in the spleen or liver. This type of haemolysis is commonly seen in haemoglobinopathies such as sickle cell anaemia and thalassaemia, hereditary spherocytosis, haemolytic disease of the newborn, and warm autoimmune haemolytic anaemia.

It is important to understand the site of haemolysis in order to properly diagnose and treat haemolytic anaemias. While both intravascular and extravascular haemolysis can lead to anaemia, the underlying causes and treatment approaches may differ.

The Role and Composition of Bile

Bile plays a crucial role in the excretion of substances that are not easily eliminated by the kidneys, particularly lipid-rich molecules and non-polar substances. Its main components include bile acids or bile salts, cholesterol, phospholipids (such as lecithin), conjugated bilirubin, electrolytes, and a small amount of protein. Glucose is not typically found in bile as it is highly soluble and can be excreted in urine if present in excess in the bloodstream.

Cholesterol is broken down into bile acids, specifically cholic acid and chenodeoxycholic acid, which are then conjugated with proteins like glycine or taurine to form bile salts. Conjugated bilirubin, on the other hand, is a byproduct of the breakdown of haem from haemoglobin and myoglobin. Overall, bile serves as an important mechanism for the elimination of certain substances from the body.

In the treatment of anaphylaxis, IM adrenaline holds the utmost significance while hydrocortisone/chlorphenamine are no more administered.

Anaphylaxis is a severe and potentially life-threatening allergic reaction that affects the entire body. It can be caused by various triggers, including food, drugs, and insect venom. The symptoms of anaphylaxis typically develop suddenly and progress rapidly, affecting the airway, breathing, and circulation. Swelling of the throat and tongue, hoarse voice, and stridor are common airway problems, while respiratory wheeze and dyspnea are common breathing problems. Hypotension and tachycardia are common circulation problems. Skin and mucosal changes, such as generalized pruritus and widespread erythematous or urticarial rash, are also present in around 80-90% of patients.

The most important drug in the management of anaphylaxis is intramuscular adrenaline, which should be administered as soon as possible. The recommended doses of adrenaline vary depending on the patient’s age, with the highest dose being 500 micrograms for adults and children over 12 years old. Adrenaline can be repeated every 5 minutes if necessary. If the patient’s respiratory and/or cardiovascular problems persist despite two doses of IM adrenaline, IV fluids should be given for shock, and expert help should be sought for consideration of an IV adrenaline infusion.

Following stabilisation, non-sedating oral antihistamines may be given to patients with persisting skin symptoms. Patients with a new diagnosis of anaphylaxis should be referred to a specialist allergy clinic, and an adrenaline injector should be given as an interim measure before the specialist allergy assessment. Patients should be prescribed two adrenaline auto-injectors, and training should be provided on how to use them. A risk-stratified approach to discharge should be taken, as biphasic reactions can occur in up to 20% of patients. The Resus Council UK recommends a fast-track discharge for patients who have had a good response to a single dose of adrenaline and have been given an adrenaline auto-injector and trained how to use it. Patients who require two doses of IM adrenaline or have had a previous biphasic reaction should be observed for a minimum of 6 hours after symptom resolution, while those who have had a severe reaction requiring more than two doses of IM adrenaline or have severe asthma should be observed for a minimum of 12 hours after symptom resolution. Patients who present late at night or in areas where access to emergency care may be difficult should also be observed for a minimum of 12