Although approximately 15 years have passed since collagen
was identified as an allergen, there are few reports on fish collagen
as an allergen. Recently, we revealed that 50% of Japanese patients
with fish allergies have specific IgE against fish collagen.28 Antibodies
against fish collagen cross-react with collagens of various
fish species but not with mammalian and avian collagens.23,28 The
IgE reactivities of patients' sera against fish collagen are stable after
collagen is heated at 100 C for 120 min.23 However, the thermostability
of fish collagen at temperatures higher than 100 C, or
upon heating for more than 120 min, is unknown. When fish is
cooked, it is usually heated at over 100 C or for a prolonged time of
over 120 min by various methods, such as boiling, steaming, grilling,
baking, and frying, especially in Asian countries. Therefore, in
the present study, we investigated the IgE reactivity of patients'
sera to fish extracts prepared from heated fish meat. Further, to
determine the thermostability of the allergenicity of fish collagen,
we administered skin prick tests (SPTs) to a patient sensitized to
fish collagen.