EM, EN and vasculitis PDF

Erythema multiforme Cause Reaction to an infection (90% of cases), often herpes Course simplex, or to a drug and 50% of cases have no Crops of new lesions appear for 1...

Erythema multiforme Cause Reaction to an infection (90% of cases), often herpes Course simplex, or to a drug and 50% of cases have no Crops of new lesions appear for 1–2 weeks, or until the demonstrable provoking factor. responsible drug or another factor has been eliminated. Individual lesions last several days. The site of resolved lesions is marked transiently by grey Presentation or brown patches. symptoms of an upper respiratory tract infection may A recurrent variant of erythema multiforme exists, precede the eruption. characterized by repeated attacks, in which lesions Typically, annular non-scaling plaques appear continue to develop over a prolonged period, even for predominantly on acral sites: the palms, soles, forearms, years. and legs. Herpes simplex infection is thought to be the most Individual lesions enlarge but clear centrally. prevalent precipitant in these cases. A new lesion may begin at the same site as the original one, so that the two concentric plaques look like a target. Complications In erythema multiforme major there is involvement of There are usually no complications. the mucous membranes (oral, genital, ocular, pharyngeal However, severe lesions in the tracheo-bronchial tree of or with prodromal symptoms of fever, myalgia, and patients with erythema multiforme major can lead to malaise. asphyxia, and ulcers of the bulbar conjunctiva to Some lesions blister. blindness. The Stevens–Johnson syndrome is now no longer Corneal ulcers, anterior uveitis and panophthalmitis may thought to be a severe form of erythema multiforme but also occur. rather part of the toxic epidermal necrolysis (TEN) spectrum Genital ulcers can cause urinary retention, and of diseases. phimosis or vaginal stricture after they heal. Differential diagnosis: Stevens–Johnson syndrome, extensive erythematous Treatment targetoid macules show an initial preponderance for the The best treatment is to identify an underlying cause trunk, associated with significant mortality. and remove it. The annular variant of urticaria, persistence of lesions In mild cases, only symptomatic treatment is needed, for longer than 24 hours and the involvement of mucous and this includes the use of antihistamines. membranes favor a diagnosis of erythema multiforme. Erythema multiforme major, demand consultation Fixed drug eruptions between dermatologists and specialists in other fields such Sweet’s syndrome as ophthalmology, urology, and infectious diseases, bullous disorders depending on the particular case. Rings of granuloma annulare take weeks or months to Oral mucosal involvement may be treated with topical develop. steroids, in severe cases where pain impedes swallowing, systemic steroids may be needed. Investigations Herpes simplex infections should be suspected in Histology: recurrent or continuous erythema multiforme of otherwise -epidermal necrosis and dermal changes: unknown cause. -endothelial swelling A6-month trial of continuous treatment with oral -mixed lymphohistiocytic perivascular infiltrate valaciclovir or famciclovir may prevent attacks, both of -papillary dermal oedema. herpes simplex and of the recurrent erythema multiforme Most investigations are directed towards identifying a that follows it. cause. A careful history helps rule out a drug reaction. Learning points A PCR test, Tzanck smear or culture of suspicious Look for target lesions and involvement of the palms. prodromal vesicles for herpes simplex infection Herpes simplex infection is the most common provoking A chest X-ray and serological tests should identify factor of recurrent erythema multiforme, but do not forget mycoplasma pneumonia. drugs. A search for other infectious agents, neoplasia, endocrine causes, or connective tissue disorder is sometimes necessary, if prolonged or recurrent. Erythema nodosum Differential diagnosis Erythema nodosum is an inflammation of the The differential diagnosis of a single tender red nodule subcutaneous fat (a panniculitis). is extensive and includes trauma, infection (early cellulitis It is septal panniculitis, with inflammation confined to or abscess) if multiple infection is less likely and phlebitis. the fibrous septae running between the fat lobules. Other causes of a nodular panniculitis, which may type IV delayed hypersensitivity reaction elicited by appear like erythema nodosum, include panniculitis from various bacterial, viral, and fungal infections, malignant pancreatitis, cold, trauma, the injection of drugs or other disorders, drugs or by a variety of other causes foreign substances, withdrawal from systemic steroids, lupus erythematosus, superficial migratory thrombophlebitis, polyarteritis nodosa and a deficiency of Presentation α1-antitrypsin. tender red nodule developing alone or in groups on the legs and forearms or, rarely, on other areas such as the thighs, face, breasts, or other areas where there is fat. Investigations Some patients also have painful joints and fever. careful history, physical examination chest X-ray Course throat culture for streptococcus, Individual lesions resolve over 2 weeks with new ‘crops’ anti-streptolysin O(ASO) titer appearing for up to 6–8 weeks. Mantoux test Persisting erythema nodosum is sometimes called Serological testing for deep fungal infections such as nodular vasculitis. coccidioidomycosis at least in endemic areas. Pregnancy should be excluded. Complications If the results are normal, and there are no symptoms or The nodules may be so tender that walking is difficult. physical findings to suggest other causes, extensive Erythema nodosum leprosum occurs when lepromatous investigations can be deferred because the disease will leprosy patients establish cell-mediated immunity to usually resolve. Mycobacterium leprae. These patients have severe malaise, arthralgia, and fever. Treatment identify and eliminate its cause if possible. For example, if culture or an ASO test confirms a streptococcal infection, a suitable antibiotic should be recommended. Bed rest and leg elevation are also an important part of treatment. NSAIDs such as aspirin, indomethacin or ibuprofen may be helpful. Systemic steroids are usually not needed. For reasons that are not clear, potassium iodide in a dosage of 400–900 mg/day can help but should not be used for longer than 6 months.  Some have a small, livid, or black center, caused by Vasculitis necrosis of the tissue overlying the affected blood vessel. Vasculitis is an inflammation within the vessel wall, with Henoch–Schoenlein purpura is a small vessel vasculitis endothelial cell swelling, necrosis or fibrinoid change. associated with palpable purpura, arthritis, abdominal The clinical manifestations depend upon the size of the pain and occasionally nephritis. blood vessel affected. It typically presents in children following an upper respiratory tract infection. Cutaneous small vessel vasculitis (involving small vessels) Syn: cutaneous leucocytoclastic angiitis, leucocytoclastic Urticarial vasculitis is a small vessel vasculitis characterized vasculitis, allergic or hypersensitivity vasculitis, by burning urticaria-like lesions (rather than itching found anaphylactoid purpura in true urticaria), which last for longer than 24 hours, sometimes leaving bruising and then pigmentation at the Cause site of previous lesions. Immune complexes lodge in the walls of blood vessels There may be foci of purpura in the wheals, low serum (principally the postcapillary venules), complement levels, elevated ESR and sometimes activate complement and attract polymorphonuclear angioedema. leucocytes which damage vessel wall. General features include malaise and arthralgia. Antigens in these immune complexes include drugs, autoantigens, and infectious agents such as viruses and Course bacteria. The course of vasculitis varies with its cause, its extent, the size of blood vessel affected and the involvement of Presentation other organs. The most common presentation of cutaneous small In cutaneous small vessel vasculitis spontaneous vessel vasculitis is painful palpable purpura. resolution occur. in dependent areas (the forearms and legs in However, up to 10% of patients may have repeated ambulatory patients, or on the buttocks and flanks in episodes. bedridden ones.) In Henoch–Schoenlein purpura the presence of nephritis predicts a worse long-term prognosis. Complications The finding of circulating immune complexes, or a The vasculitis may simply be cutaneous, may be systemic lowered level of total complementor C4, will implicate and then other organs will be damaged, including the immune complexes as its cause. kidney, central nervous system, gastrointestinal tract, and Tests for paraproteins, hepatitis viruses, cryoglobulins, lungs. rheumatoid factor, antineutrophil cytoplasmic antibody (ANCA) and antinuclear antibodies may also be needed. Differential diagnosis Henoch–Schoenlein vasculitis is confirmed if IgA Abnormalities of the clotting system and sepsis (with or deposits are found in the blood vessels of a patient without vasculitis). with the clinical triad of palpable purpura, arthritis and Vasculitic purpuras are raised (palpable). abdominal pain. Occasionally, the vasculitis may look like urticaria if its purpuric element is not marked. Treatment Blanching such an urticarial papule with a glass slide The treatment of choice is to identify the cause and (diascopy) may reveal subtle residual purpura. eliminate it. antihistamines, and bed rest sometimes help. Investigations Colchicine 0.6 g twice daily or dapsone 100 g daily may identifying the cause be worth a trial but require monitoring for side effects Questioning may indicate infections; myalgias, Patients whose vasculitis is damaging the kidneys or abdominal pain, claudication, mental confusion and other internal organs may need systemic corticosteroids or mononeuritis may indicate systemic involvement. immunosuppressive agents such as cyclophosphamide. A physical examination, chest X-ray, ESR and biochemical NSAIDs may be useful in treating painful skin lesions and tests monitoring the function of various organs are associated arthralgias but should be avoided if there is indicated. renal involvement. the most important test is urine analysis, checking for proteinuria and hematuria because vasculitis can affect the kidney subtly and so lead to renal insufficiency, the blood pressure should also be checked. Skin biopsy will confirm the diagnosis. Wegener’s granulomatosis (involving small and medium-sized vessels) Splinter hemorrhages and livedo reticularis aid the clinical diagnosis. granulomatous vasculitis of unknown cause, 10% of cases is limited to the skin (cutaneous fever, weight loss and fatigue, naso-respiratory polyarteritis nodosa); in the remainder there is systemic symptoms such as rhinitis, hearing loss or sinusitis. involvement of the kidneys, gut, heart muscle, nerves, 50% have skin lesions, usually symmetrical ulcers, or testicles, and joints. papules on the extremities. Cutaneous polyarteritis nodosa is associated with the eye, joints, heart, nerves, lung, and kidney can be streptococcal infection in children. affected. Patients may be febrile, lose weight and feel pain in the Antineutrophil antibodies (usually C-ANCA with muscles, joints, or abdomen, some develop peripheral anti-PR3 specificity) are present in most cases and are neuropathy, hypertension, and ischemic heart disease. a useful but non-specific diagnostic marker. Renal involvement, with or without hypertension, Cyclophosphamide is the treatment of choice, used is common. alone or with systemic steroids. Course Polyarteritis nodosa (involving medium-sized Untreated, systemic polyarteritis nodosa becomes vessels) chronic. Cause Death, often from renal disease, is common, even in necrotizing vasculitis causes skin nodules, infarctive treated patients. ulcers and peripheral gangrene. Immune complexes may initiate this vasculitis, and Differential diagnosis sometimes contain hepatitis B or C virus or Embolism, panniculitis, and infarctions. Antigen, B-cell lymphomas, and immunotherapy. Other vasculitis and SLE. arthritis. Presentation pyoderma gangrenosum. Tender subcutaneous nodules appear along the line of arteries that may ulcerate or become necrotic. Investigations Elevated ESR, neutrophil count and gammaglobulin level Investigations for cryoglobulins, rheumatoid factor, antinuclear antibody, ANCA, hepatitis C antibodies and hepatitis B surface antigen are worthwhile, as are checks for disease in the kidneys, heart, liver, and gut. Low levels of complement C4 suggest active disease. The use of a biopsy to confirm the diagnosis of medium- sized vessel vasculitis is not always easy as the arterial involvement may be segmental, and surgery itself difficult. Affected vessels show aneurysmal dilatation or necrosis, fibrinoid changes in their walls and an intense neutrophilic infiltrate around and even in the vessel wall. Treatment Systemic steroids and cyclophosphamide improve the chances of survival. Low-dose systemic steroids alone, or methotrexate, are usually sufficient for the purely cutaneous form. Empirical penicillin is often given to children with cutaneous polyarteritis nodosa given the association with streptococcal infection. Done by: Ayman Shatnawi