Kumar & Clarks Clinical Medicine

In more severe cases, dystonia, dysphagia, muscle weakness, paralysis, ataxia and respiratory depression occur. In one outbreak involving 187 cases, there were 26 deaths. Viperidae Russell’s viper causes most of the snake-­bite mortality in India, Pakistan and Myanmar. There is local swelling at the site of the bite, which may become massive. Evidence of systemic involvement occurs within 30 minutes, including vomiting, shock and hypotension. Exposure to lead occurs occupationally, children may eat lead-­ painted items in their homes , and the use of lead-­containing cosmetics or ‘drugs’ has also resulted in poisoning.

Ganglion A ganglion is a jelly-­filled, often painless swelling caused by a partial tear of the joint capsule or tendon sheath. Treatment is not essential, as many resolve or cause little trouble; otherwise, surgical excision is the best option. Scaphoid fractures These cause pain in the anatomical snuffbox. They are not seen immediately on X-­ray; if there is clinical suspicion, a cast is necessary.

Kumar & Clarks Clinical Medicine

Following the sting or bite, patients should be observed for 2 hours for any signs of evolving urticaria, pruritus, bronchospasm or oropharyngeal oedema. The onset of anaphylaxis requires urgent treatment (see p. 64). Ciguatera fish poisoning Over 400 fish species have been reported as ciguatoxic , though barracuda, red snapper, amberjack and grouper are most commonly implicated. Ciguatera fish contain ciguatoxin, maitotoxin and scaritoxin, which are lipid-­soluble, heat-­stable compounds that are derived from dinoflagellates such as Gambierdiscus toxicus.

Since carbamates have a shorter duration of action than organophosphorus insecticides, pralidoxime should be used only rarely in carbamate poisoning. If intoxication is life-­threatening, give intravenous pralidoxime chloride 30 mg/kg body weight over 5–10 minutes, followed by an infusion of 8–10 mg/kg per hour. Clinical features Acute ingestion causes abdominal pain, vomiting and diarrhoea. Hypovolaemic shock and acute tubular necrosis occur in severe cases. Measurement of the serum lithium concentration confirms the diagnosis.

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Examine for anterior thigh pain during a femoral stretch test , which indicates a high lumbar disc problem. Management Initial treatment Treatment should be initiated immediately after the diagnosis is confirmed. In younger patients without co-­morbidity there is a high expectation of cure.

In refractory or relapsing cases, instilling faeces from the bowel of a healthy donor can restore normal bowel flora and eradicate the C. Tenosynovitis The finger flexor which cbd oil is best for parkinson’s disease uk tendons run through synovial sheaths and under loops that hold them in place. Inflammation occurs with repeated or unaccustomed use, or in inflammatory arthritis.

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Resistance to sulphonamides is often plasmid-­ mediated and results from the production of a sulphonamide-­resistant dihydropteroate synthase. Sulphonamides potentiate oral anticoagulants and some hypoglycaemic agents. The adverse effects of co-­ trimoxazole are most commonly due to the sulphonamide component. Sulphonamides cause a variety of skin eruptions, including toxic epidermal necrolysis, the Stevens–Johnson syndrome, thrombocytopenia, folate deficiency and megaloblastic anaemia with prolonged usage. They can provoke haemolysis in individuals with glucose-­6-­phosphate dehydrogenase deficiency and therefore should not be used in such people.

That resemble cDCs (e.g. the Langerhans cell in the skin; see Ch. 22). Immature cDCs and pDCs are ­present in the blood but at very low levels (80%). Resistance is also an emerging problem among Salmonella, Vibrio cholerae, S. Gastrointestinal disturbances, photosensitive rashes and occasional neurotoxicity can occur. Use should be avoided in pregnancy and childhood, and in patients taking corticosteroids, unless the benefit outweighs the risk. Tendon damage, including rupture, can occur within 48 hours of use.

The scarring and atrophy that accompany longstanding LS cause changes in the vulval structure, with loss and fusion of the labia minora and scarring of the clitoral hood. Involvement of the foreskin can cause phimosis, and urethral disease may cause strictures and impaired micturition. Profound sexual dysfunction can result from LS in both men and women. Some show a paradoxical rise; about 25% of acromegalics have a positive diabetic glucose tolerance test.

Hypothermia, hypoglycaemia and convulsions are occasionally observed in severe cases. Non-­ cardiogenic pulmonary oedema has been reported in severe heroin overdose. See page 141 for more information about the worldwide opioid crisis. Coarctation of the aorta A coarctation of the aorta is a narrowing of the aorta at, or just distal to, the insertion of the ductus arteriosus (distal to the origin of the left subclavian artery; Fig. 30.97).

Quinine cardiotoxicity is due to sodium-­channel blockade. Patients may also develop ocular features, including blindness, which can be permanent. Anticonvulsants Clinical features The clinical features of poisoning with anticonvulsant drugs are summarized in Box 12.24. Fosfomycin This is a relatively old antibiotic that has been used in some European countries for many years. It requires a functional sugar transport system (glucose-­6-­phosphate) for uptake by Enterobacterales, thus requiring modifications to standard susceptibility testing methods.

In infants, eczema often starts on the cheeks before spreading to the body. Clinical features of acute or chronic eczema may predominate and the pattern can change with time. Pruritus is usually severe, leading to excoriations and lichenification. In dark skin types the distribution may be different, with an ‘inverse pattern’ predominantly affecting the extensor surfaces, and follicles can be prominent. Pigmentary changes – hyper-­and hypopigmentation – may follow the inflammatory phase of eczema and are often slow to resolve. In some atopic individuals the skin of the upper arms and thighs feel rough due to follicular hyperkeratosis (‘keratosis pilaris’).

Treatment is with combination oral antibiotics (e.g. clarithromycin and ciprofloxacin) for 8–12 weeks, according to microbiological guidance. 670 Dermatology rapidly along tissue planes, causing spreading erythema, swelling, pain and sometimes tissue crepitus. Patients are typically febrile and severely unwell, and urgent surgical intervention and intravenous antibiotic therapy are required. High-­ dose benzylpenicillin and clindamycin are used in confirmed GAS infection, and a broad-­spectrum antibiotic combination with additional metronidazole is used where the pathogen is unknown.

Investigations These are similar to those for short stature which may coexist and should include thyroid function and bone age. Assessment of LH, FSH, oestradiol or testosterone will identify primary hypogonadism. Low normal gonadotrophins with low oestradiol or testosterone may either represent secondary hypogonadism or constitutional delay. In paediatric practice an LHRH may also be performed, although the discriminatory value of this test is low. In girls with primary amenorrhoea, assessment for pelvic abnormalities is essential and if the uterus is absent further investigations for disorders of sex development are warranted.

Small defects may predispose to endarteritis and should be considered for device closure unless clinically silent. Investigations and treatment • C  hest X-­ray in an adult with a significant left-­to-­right shunt will show enlarged pulmonary arteries and an increased cardiothoracic ratio . • ECG may demonstrate left atrial abnormality and high-­voltage QRS complexes related to left heart overload. If there is right axis deviation and a tall R in V1, this may represent established Eisenmenger’s syndrome.

Diagnosis is confirmed by measuring the erythrocyte cholinesterase activity. Calcium-­channel blockers Calcium-­channel blockers all act by blocking voltage-­gated calcium channels. Dihydropyridines (e.g. amlodipine, felodipine, nifedi­ pine) are predominantly peripheral vasodilators, while verapamil and diltiazem also have significant cardiac effects. Poisoning, particularly with verapamil and diltiazem, causes heart block and hypotension; in severe poisoning, there is a substantial fatality rate. When a sustained-­release prep­ aration has been ingested, the onset of severe features is delayed, sometimes for more than 12 hours. Overdose with even small amounts can have profound effects.

The resulting systemic venous congestion produces hepatomegaly, ascites and dependent oedema. Investigations Chest X-­ray The chest X-­ray features are those of left ventricular enlargement and, possibly, dilation of the ascending aorta. The ascending aortic wall may be calcified in syphilis, and the aortic valve calcified if valvular disease is responsible for the regurgitation.

Clinical features The majority of patients present with painless lymphadenopathy clinically, at one or several sites. Intra-­abdominal disease presents with bowel symptoms due to compression or infiltration of the gastrointestinal tract. In a small proportion, there is a primary mediastinal presentation, with symptoms and signs akin to those of HL. There may be ‘B’ symptoms, which should not be confused with symptoms related to the site of involvement. Investigation will lead to the demonstration of either locally or systemically advanced disease in the majority of cases. The illness is itself rapidly progressive without intervention, death occurring within months rather than years.

Whereas most ligaments and tendons run outside the joints, some, like the supraspinatus tendon in the shoulder and the cruciate ligaments in the knee, run through the joint. Inflammation or trauma to these joints can cause severe joint symptoms. Specific poisons 276.e7 Cytotoxic mushrooms Cytotoxic mushroom poisoning is caused Was ist der Unterschied zwischen CBD-Öl und einer CBD-Tinktur? by amatoxins and orellanin. Amatoxins inhibit transcription from DNA to mRNA by the blockade of nuclear RNA polymerase II; this results in impaired protein synthesis and cell death. Jellyfish stings Most of the jellyfish found in North European coastal waters are non-­toxic, as their stings cannot penetrate human skin.

Kumar & Clarks Clinical Medicine

Side-­effects, which prevent effective therapy in a minority of cases, include nausea and vomiting, dizziness and syncope, constipation and cold peripheries. Complications, seen when cabergoline is used in higher doses in Parkinson’s disease, include pulmonary, retroperitoneal and pericardial fibrotic reactions, and cardiac valve lesions. Patients need monitoring, although studies suggest that adverse effects appear to be very rare in those on lower, ‘endocrine’ doses. In addition, patients can also develop neuropsychiatric side-­effects, including compulsive behaviours such as gambling. Prolactinomas usually shrink in size on a dopamine agonist, and in macroadenomas any pituitary mass effects commonly resolve (Fig. 21.36).

These include intravenous fluids with volume expanders for hypotension and diazepam for anxiety. Treatment of acute respiratory, cardiac and kidney injury is instituted as necessary. Antivenoms are not generally indicated unless envenomation is present, as they can cause severe allergic reactions. Antivenoms can rapidly neutralize venom, but only if an amount in excess of the amount of venom is given. Large quantities of antivenom may be required; as antivenoms cannot reverse the effects of the venom, they must be given early to minimize some of the local effects and may prevent necrosis at the site of the bite.

Antimalarials Chloroquine Severe poisoning may present with hypotension, cardiac failure, pulmonary oedema and cardiac arrest. Agitation, acute psychosis, convulsions and coma may occur. Hypokalaemia is common and is due to chloroquine-­induced potassium-­channel blockade. Bradyarrhythmias and tachyarrhythmias are common, and ECG conduction abnormalities are similar to those seen in quinine poisoning. Intravenous glucose may be required to treat hypoglycaemia.

Investigation in some patients; full pituitary evaluation may be required in such cases to exclude other pituitary disease. De Quervain’s thyroiditis This is transient hyperthyroidism from an acute inflammatory process, probably viral in origin. Apart from the toxicosis, there is usually fever, malaise and pain in the neck with tachycardia and local thyroid tenderness.

The likely affected system as suggested by the history, and finally a wider examination of other organ systems. 1.2 outlines a typical general and systematic examination routine suitable for use in patients presenting with a wide range of medical conditions. The ‘Clinical skills’ sections at the beginning of many of the chapters in this book offer tailored versions of this basic routine relevant to patients with specific types of complaint.

The cause is thought to be relative oestrogen excess, and the oestrogen antagonist tamoxifen is occasionally helpful. History and examination The usual presentation is simply hypertension; hypokalaemia (99%) are caused by intrinsic thyroid disease; a pituitary cause is extremely rare (Box 21.28). Most common patterns of hyperthyroidism and their distinctive features are outlined in Box 21.29.

Muscle fasciculation and flaccid paresis of limb muscles, and, occasionally, paralysis of extraocular muscles is observed. Clinical features Methanol causes inebriation and drowsiness. Blurred vision and diminished visual acuity occur due to formate accumulation. The presence of dilated pupils that are unreactive to light suggests that permanent blindness is likely to ensue.

As glucose concentration falls below the normal range, glucagon is secreted from the pancreatic α-­cells. At the same time, a number of other hormones, including noradrenaline , cortisol and growth hormone, are released. These counter-­regulatory hormones increase hepatic glucose production and reduce its utilization in fat and muscle for any given insulin concentration. Pale patches may be left after resolution of an inflammatory complaint, especially eczema and psoriasis.

Echocardiogram The echocardiogram (Fig. 30.85) demonstrates vigorous cardiac contraction and a dilated left ventricle. Diastolic fluttering of i spark change taking on the challenge of changing the world the mitral leaflets or septum occurs in severe aortic regurgitation . TOE may provide additional information about the valves and aortic root.

Several of these loci define β cell development or function, and there is no overlap with the immune function genes identified for type 1 diabetes. Transcription factor-­7-­like 2 (TCF7-­L2) is the most common variant observed in type 2 diabetes in Europeans, and KCNQ1 (a potassium voltage-­gated channel) in Asians. Most of the identified genetic markers exert very modest risk and together explain less than 20% of the heritability of type 2 diabetes. Over several years and has an asymmetrical border and irregular pigmentation. Lentigo maligna represents a slow-­growing intraepidermal form of melanoma, similar to a melanoma in situ, where malignant cells grow radially without dermal invasion.

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These imbalances may be acute or chronic, may occur with varying degrees of severity, and may or may not be partially compensated by the body’s regulatory mechanisms. Extended-­spectrum β-­lactamase-­producing ­Enterobacteriaceae ESBLs are inactivating enzymes that confer resistance to most β-­ lactam antibiotics, Is Delta 8 THC Addictive? including penicillins, cephalosporins and aztreonam. Coli of the CTX-­M-­15 type suddenly emerged in 2004 and approximately 15% of all E. The most common sites of infection for ESBL-­producing Enterobacteriaceae are the urinary tract and, less frequently, the gastrointestinal or hepatobiliary tract.

Infection is usually food-­or water-­borne and younger travellers are most often affected . Reported attack rates vary from country to country but approach 50% for a 2-­week stay in some nations. The disease is usually benign and self-­limiting; treatment with quinolone antibiotics may hasten recovery but is not normally necessary. Prophylactic antibiotic therapy may also be effective for short stays but should not be used routinely. A large central disc prolapse is shown at the C6/7 level, and smaller disc bulges at C3/4 and C4/5. MRI is the investigation of choice if surgery is being considered or the diagnosis is uncertain (Fig. 18.4).

In adults, clinical features and biochemistry (plasma renin, androstenedione and 17-­hydroxyprogesterone) are used to modify treatment. The use of modified-­release hydrocortisone may have a role in the management of CAH. Dupuytren’s contracture This condition is a painless, palpable fibrosis of the palmar aponeurosis, with fibroblasts invading the dermis. It causes puckering of the skin and gradual fixed flexion, usually of the ring and little fingers. It is more common in males, Caucasians, individuals with diabetes mellitus, and those who overuse alcohol.

Closure of an ASD is indicated if there is a significant left-­to-­ right shunt, resulting in right atrial and ventricular enlargement with normal pulmonary vascular resistance and oxygen saturations. Management Management of severe pulmonary stenosis requires pulmonary valvotomy . Treatment is reserved for patients unfit for surgery or as a ‘bridge’ to surgery . Cardiac catheterization Left and right heart catheterization is appropriate for patients referred for surgical repair or replacement.

It usually starts a few days after drug exposure and resolves with peeling. There may be mild systemic upset but internal organs are not involved. Topical steroids and emollients can be used to relieve symptoms. Features are present, a full endocrine assessment is necessary. Hirsutism can cause severe psychological distress in some individuals. Management involves physical methods, such as bleaching, waxing, electrolysis, intense pulsed light and laser therapy.

Management Glucocorticoid activity must be replaced, as must mineralocorticoid activity if deficient. The practice in CAH of giving the larger dose of glucocorticoid at night to suppress the morning ACTH peak, with a smaller dose in the morning, is largely outdated. Correct dosage is often difficult to establish in the child but should ensure normal androstenedione and mildly elevated 17OHP levels while allowing normal growth; excessive replacement leads to stunting of growth.

Sulphonamides and trimethoprim The sulphonamides are all derivatives of the prototype sulfanilamide, and act by blocking thymidine and purine synthesis by inhibiting microbial folic acid synthesis. Trimethoprim is a 2,4-­diaminopyrimidine, which prevents the bacterial reduction of dihydrofolate to tetrahydrofolate. Sulfamethoxazole is mainly used in combination with trimethoprim (as co-­trimoxazole). Difficile infection and remains useful for some resistant Gram-­ negative infections. Trimethoprim alone is often used for empirical treatment of UTIs.

Occasionally, arsenic is found in Chinese and Indian traditional remedies. Clinical features Benzodiazepines produce drowsiness, ataxia, dysarthria and nystagmus. Coma and respiratory depression develop in severe intoxication.

Kumar & Clarks Clinical Medicine

Finasteride is well tolerated but may cause sexual adverse effects, such as loss of libido in about 1% of men; it should not be taken or handled by pregnant women, as it can cause feminization of a male fetus. Oral antiandrogen therapy (e.g. cyproterone acetate or spironolactone) may help some women. Management of short stature Systemic illness should be treated and primary hypothyroidism managed with levothyroxine. A watch and wait approach to those with constitutional delay, potentially with a very-­ low-­ dose sex steroids in 3-­to 6-­ month courses to kick-start puberty and induce acceleration of growth.

Sheehan’s syndrome This is due to pituitary infarction following postpartum haemorrhage and is rare in developed countries but not uncommon in countries where there are not established obstetric services. Hypophysitis and other inflammatory masses Reduction of excess hormone secretion Reduction is usually obtained by surgical removal but sometimes by medical treatment. Useful control can be achieved with dopamine agonists for prolactinomas or somatostatin analogues for acromegaly, but ACTH secretion usually cannot be controlled by medical means.

Their bites occur in groups or lines as intensely itchy papules on exposed areas, including the face and neck. Infestations usually require expert pest control for eradication. Further advice may be obtained in the UK from the National Pest Technicians Association, a professional trade body .

Medical causes of pruritus should be excluded (see Box 22.20). Venous eczema Venous eczema usually affects the elderly and those with varicose veins or a history of venous thrombosis. The inner calf is involved and there are usually coexistent signs of venous hypertension, including haemosiderin deposition, lipodermatosclerosis and varicose ulceration. The eczematous changes range from mild erythema and scaling to an acute exudative inflammatory rash.

In females, the usual age of onset is before puberty or after the menopause. Lesions are intensely pruritic or sore, and appear as shiny, ivory–white, fissured patches on the vulva, or on the glans penis and distal foreskin or penile shaft. Additional perianal involvement is common in females, leading to a ‘figure-­of-­eight’ distribution. Telangiectasia may be evident, and early lesions in girls can present with haemorrhagic blisters that are occasionally mistaken for signs of sexual abuse.

Once the pain settles, arthroscopic release speeds functional recovery. Nerve root entrapment This is caused by an acute cervical disc prolapse or pressure on the root from spondylotic osteophytes narrowing the root canal. Acute cervical disc prolapse presents with unilateral pain in the neck, radiating to the interscapular and shoulder regions. This diffuse, aching, dural pain is followed by sharp, electric shock-­like pain down the arm, in a nerve root distribution, often with pins and needles, numbness, weakness and loss of reflexes (Box 18.9). An MRI scan clearly distinguishes facet joint OA, root canal narrowing and disc prolapse.

The insulin receptor consists of α-­ and β-­subunits linked by disulphide bridges . The transporter protein GLUT-­4 is stored in intracellular vesicles. The binding of insulin to its receptor initiates many intracellular actions, including translocation of these vesicles to the cell membrane, carrying GLUT-­4 with them; this allows glucose transport into the cell. Affected, especially in Western countries, have type 1A disease.

No systemic treatment is required except in cases of severe systemic toxicity, when specific antivenom should be given, if this is available. Exposure to phosphine causes lacrimation, rhinorrhoea, cough, breathlessness, chest tightness, dizziness, diplopia, headache, nausea, drowsiness, intention tremor and ataxia. Acute pulmonary oedema, hypertension, cardiac arrhythmias, convulsions and jaundice have been described in severe cases.

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Myeloma and other plasma cell disorders 409 • M  RI spine. This is useful if there is back pain; it may show imminent compression or collapse. how to use cbd peppermint oil Haemoglobin, white cell count and platelet count are normal or low. There may be rouleaux formation as a consequence of the paraprotein.

Local analgesia and antihistamine creams provide symptomatic relief. Other features should be treated symptomatically and supportively. Skin infections 671 Mycobacterial infections Leprosy (Hansen’s disease) Leprosy (see p. 550) typically involves the skin and peripheral nerves. The clinical features depend on the host’s immune response to the infecting organism, Mycobacterium leprae. Tuberculoid leprosy presents with a few larger, hypopigmented (see Fig. 20.24) or erythematous plaques with an inflamed border. Sensation is absent within lesions, which are dry and hairless due to nerve damage.

Bariatric surgery is indicated for those with hypertension and a body mass index of more than 35 kg/m2, but it is not commonly performed without the additional co-­ morbidity of type 2 diabetes. Recent data confirm the profound BP-­lowering effect of such surgery, which may be due to additional gut hormonal changes postoperatively, in addition to expected weight loss. Congenital heart disease 1111 Life expectancy is normal in silent PDAs and patients who have had appropriate and timely closure of a PDA. Indications for intervention include left ventricular dilation with significant shunt and no significant pulmonary vascular disease .

Gonadotrophin-­independent precocious puberty The most common cause is congenital adrenal hyperplasia. Other causes include testicular or ovarian disorders, such as testotoxi­ cosis or McCune–Albright’s syndrome (MAS; see also p. 650). MAS usually occurs in girls, with precocity, polyostotic fibrous dysplasia and skin pigmentation (café-­ au-­ lait patches). HCG-­ secreting tumours, androgen-­and oestrogen-­ secreting tumours, including teratomas, are important conditions to exclude. Gynaecomastia in the older male This requires a full assessment to exclude potentially serious underlying disease, such as bronchial carcinoma and testicular tumours (e.g. Leydig cell tumour). However, aromatase activity (see p. 624) increases with age and may be the cause of gynaecomastia in this group.

Oculocutaneous albinism This rare group of autosomal recessive disorders is caused by reduced or absent pigment synthesis in the skin, hair and eyes. Individuals have pale skin, white or yellow hair, and a pink iris. Ocular manifestations include photophobia, nystagmus and a squint.

Aortic regurgitation Aortic regurgitation can occur in diseases affecting the aortic valve, such as endocarditis, and diseases affecting the aortic root, such as Marfan’s syndrome (Box 30.44). Percutaneous valve replacement A novel treatment for patients unsuitable for surgical aortic valve replacement is transcatheter aortic valve implantation , with a balloon expandable stent valve. Valve implantation has been shown to be successful (86%) with a procedural mortality of 2% and 30-­ day mortality of 12%. Good results have been reported in follow-up studies, and this technique may replace the need for surgery. Antithrombin drugs An antithrombin should be added to dual antiplatelets in patients with ACS.

These areas are particularly vulnerable to the drying effects of soap and water. The rash resembles crazy paving with dry scales and inflamed cracks. Frequent use of a bland moisturizer and soap substitute is usually all that is needed. Other rarer causes of facial rashes These include autoimmune rheumatic diseases, lymphocytic and granulomatous infiltrates. Septo-­optic dysplasia This rare congenital syndrome , presents in childhood with two out of the clinical triad of midline forebrain abnormalities, optic nerve hypoplasia and hypopituitarism. Kallmann’s syndrome This is isolated gonadotrophin deficiency (see p. 626) caused by mutations in the KAL1 gene, which is located on the short arm of the X chromosome.

Most have an abnormality of imprinting of the ZAC and HYMAI genes on chromosome 6q. The most common cause of permanent neonatal diabetes mellitus is mutations in the KCNJ11 gene encoding the Kir6.2 subunit of the β-­cell potassium–adenosine triphosphate channel. Diabetes results from defective insulin release rather than β-­cell destruction, and can be treated successfully with sulphonylureas, even after many years JustCBD – Foire aux questions of insulin therapy. Single-­dose dalbavancin may be an alternative to conventional antibiotics in the treatment of acute bacterial skin infections in adults, avoiding the need for hospitalization or repeat attendance. Up to 50% of people with cellulitis experience repeat episodes. Prophylactic antibiotic therapy reduces the risk of further attacks during treatment but the effect wears off after discontinuation.

Examples of successful interventions include campaigns for the provision of vaccines by the Global Alliance for Vaccines and Immunization and initiatives to reduce the economic exploitation of child labour. The African Programme for Onchocerciasis Control has transformed the lives of millions of people by the administration of a single, annual dose of the drug ivermectin. Supportive treatment and treatment of complications • S  hock usually results from hypovolaemia , and should be corrected with intravenous fluids. • Respiratory failure from respiratory muscle paralysis should be treated with assisted ventilation . • Paralysis due to postsynaptic neurotoxicity may respond to anticholinesterases such as neostigmine.

Calcium ions chelate oxalate to form insoluble calcium oxalate, which is responsible for renal toxicity. Cyclase and promoting formation of cyclic adenosine monophosphate from adenosine triphosphate ; cAMP, in turn, exerts a direct beta-­stimulant effect on the heart. Intravenous atropine 0.6–1.2 mg can be used to treat bradycardia but is usually less effective.

Loss of the eyebrows (‘madarosis’) and nasal stuffiness are common. Management Untreated acromegaly results in markedly reduced survival. Most deaths occur from heart failure, coronary artery disease and hypertension-­related causes. Treatment is therefore indicated in all except the elderly or those with minimal abnormalities. The aim of therapy is to achieve a mean GH level below 2.5 μg/L; this is not always ‘normal’ but has been shown to reduce mortality to normal levels and is therefore considered a ‘safe’ GH level.

Inhalation of methylene chloride may also lead to carbon monoxide poisoning, as methylene chloride is metabolized in vivo to carbon monoxide. Carbon monoxide has a greater affinity for haemoglobin and forms carboxyhaemoglobin , thereby reducing the oxygen-­carrying capacity. The affinity of the remaining haem groups for oxygen is increased. This shifts the oxyhaemoglobin dissociation curve to the left, impairing liberation of oxygen to the cells and leading to tissue hypoxia. In addition, carbon monoxide also inhibits cytochrome oxidase a3. Clinical features Although carbamate insecticide poisoning is generally less severe than organophosphorus insecticide poisoning, acute poisoning with a carbamate can be severe and fatal.