A Case Report of Leukocytoclastic Vasculitis: Diagnostic Approach and Treatment.

BACKGROUND Leukocytoclastic vasculitis is a small-vessel vasculitis associated with infections, autoimmune disorders, and certain drugs, but it may also be idiopathic. CASE REPORT We report the case of a 37-year-old woman with no significant past medical history who presented with a chief concern of a full-body rash. Before the rash appeared, she had been treated for group A Streptococcus with amoxicillin and prednisone. An outpatient skin biopsy revealed findings concerning for early leukocytoclastic vasculitis. On admission, she had a diffuse palpable rash on the trunk and upper and lower extremities. Laboratory test results were notable for neutrophilic leukocytosis with a left shift, reticulocytosis with normal hemoglobin, thrombocytosis, and elevated ESR and CRP. An infectious diseases workup was negative, serum levels of complement C3 and C4 were normal, and no evidence of hemolysis was found on blood smear. Results of schistocytes review, LDH, and haptoglobin were not consistent with hemolysis, and IgG, IgA, and IgM were all within normal limits. The patient was initially started on antibiotics due to concern for bullous impetigo, but the treatment regimen was changed to steroids because IgA vasculitis and leukocytoclastic vasculitis were suspected. Biopsy results were received 1 week later and did not reveal definitive findings of acute leukocytoclastic vasculitis. Staining with antibodies to human IgG, IgA, IgM, C3, fibrinogen, and albumin was negative. CONCLUSIONS Leukocytoclastic vasculitis can be triggered by penicillins, cephalosporins, sulfonamides, phenytoin, and allopurinol acting as haptens and stimulating an immune response, resulting in development of vasculitis.