Allergy to human seminal fluid is a rare but potentially life-threatening disorder. Acute symptoms range from local reactions to generalized symptoms. A 30-year-old woman experienced vulvovaginal itching, erythema and swelling as well as generalized urticaria and angioedema of the neck and face after unprotected sexual intercourse. A scratch test with undiluted seminal fluid and the detection of specific IgE antibodies revealed a type I allergy to seminal fluid. Risk factors and therapeutic options are discussed.