For three years, a 35-year-old woman in Japan kept suffering severe allergic reactions at night. More than 10 times, the episodes struck one to three hours after she went to bed, bringing hives, facial swelling, trouble breathing, and abdominal pain that required emergency epinephrine injections.
Blood tests pointed to an obvious suspect: very high antibodies to Anisakis, a parasitic worm found in raw or undercooked fish. But the real trigger, according to a case report published July 29 in the Journal of Allergy and Clinical Immunology: Global, was proteins in her partner's semen. Her doctors believe it is also the first full case report of a live birth through in vitro fertilization, or IVF, in a patient with the allergy.
