Abstract
Background: OK-432, a lyophilised incubation mixture of group A Streptococcus pyogenes of human origin, was used as a sclerosant for the involution of a giant cervical cystic hygroma in a newborn. Results: There were no systemic side effects. Blood tests and double immune diffusion tests showed no systemic infection or generalised inflammatory response, or antibody production. Cellular and cytokine-induced localised inflammatory reaction within the cystic hygroma, was observed on analysis of the intracystic fluid. Conclusions: The leucocytosis induced and activated by OK-432 probably increases the endothelial permeability of the lymphatics. This probably accelerated lymph drainage leading to involution of the cystic hygroma. Intralesional injection of OK-432 was safe and effective therapy for cystic hygroma in this newborn as its inflammatory reaction was localised.