AbstractWe report 7 cases of acute fatal illness characterized by fever, diffuse erythematous rash, and progressive leukopenia occurring 10 days after surgical operation. The outcome was uniformly fatal. The biopsy findings consisted of eosinophilic individual necrosis of epidermal cells, satellite cell necrosis, basal liquefaction degeneration, and scanty cell infiltration into the dermis. T lymphocytes were found in the epidermis but Langerhans cells disappeared. These findings are compatible with acute graft‐vs‐host disease following blood transfusion. Explanations based upon drug allergy, infection, toxic shock syndrome, or toxic epidermal necrolysis seem less reasona