Histologic study of delayed reactions to coelenterates.
We studied by immunohistochemistry three cases of delayed envenomation by coelenterates. The most prominent features were the grouping of human leukocyte antigen-DR-positive cells with Langerhans cells (S-100 positive) and helper/inducer T lymphocytes (Leu-1+, Leu-3+, and Leu-4+). This indicates the possibility of a type IV immunoreaction in the delayed cutaneous lesions caused by coelenterates.