Newly Diagnosed Human Immunodeficiency Virus after Sepsis-Like Reaction to Trimethoprim-Sulfamethoxazole

A rare sepsis-like hypersensitivity reaction has been observed in persons with human immunodeficiency virus (HIV) after exposure to trimethoprim-sulfamethoxazole. This reaction most commonly occurs on rechallenge with the drug and is manifested by a syndrome resembling bacterial sepsis. The mechanism of this unusual reaction remains unclear. We describe the first case in which this severe hypersensitivity reaction was the initial manifestation of HIV.