Petechial rash on the extremities

Box 1 Causes of leucocytoclastic vasculitis 1 2 Infections: β haemolytic streptococcal infection, Clostridium difficile, Helicobacter pylori, Mycobacterium tuberculosis, bacterial endocarditis, hepatitis B, hepatitis C, HIV, measles, mumps, varicella, parvovirus B19, coxsackie virus, adenovirus Drugs: non-steroidal anti-inflammatory drugs, β lactam antibiotics, diuretics, vancomycin, ranitidine, cefuroxime, diclofenac, streptokinase, and angiotensin converting enzyme inhibitors Collagen vascular diseases: rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome, mixed cryoglobulinaemia (type II and type III) Inflammatory bowel disease: ulcerative colitis, Crohn's disease Primary systemic vasculitides: Henoch-Schönlein purpura, antineutrophil cytoplasmic antibody associated vasculitis, urticarial vasculitis, polyarteritis nodosa Other: acute haemorraghic oedema of infancy, hairy cell leukaemia, multiple myeloma, non-Hodgkin's lymphoma, prostate cancer, non-small cell lung cancer, food additives, exposure to cold Patients who present with leucocytoclastic vasculitis should have a detailed history taken, and a thorough physical examination and laboratory work-up should be performed. 2 A complete blood count, platelet count, peripheral blood smear, and coagulation studies help rule out haematological causes.