A case of late-onset snow crab anaphylaxis

Abstract

A 43-year-old woman ingested soup made from miso (fermented soy paste) and female snow crab. Two hours later, the woman bathed and went to sleep. The patient then presented with systemic urticaria seven hours following ingestion of the soup. The urticaria temporarily subsided after the patient took chlorpheniramine maleate. However, an itching sensation awoke the patient nine hours later; she briefly lost consciousness, then developed emesis and diarrhea. It is thought that she developed late-onset anaphylaxis, which did not involve immediate symptoms. After the patient recovered, prick test (PT) and scratch test (ST) were performed using snow crab tissue as an antigen. Tissue from the outer roe (zygotes) elicited positive responses, but inner roe (ovary) and tissue from the crab butter (liver and pancreas) elicited negative results. Furthermore, when the same tests were performed using muscle tissues taken from a male snow crab, a king crab, and a horsehair crab as antigens, only tissues from the male snow crab and horsehair crab elicited positive responses. The reason for the differential response is thought to be associated with the lesser degree of chromosomal crossover between the king crab species, which belongs to the infraorder Anomura along with the hermit crab, and other species of crabs, which belong to the infraorder Brachyura.