Calabar swellings

Calabar swellings are localized infections where the parasite -adult worm- is secreting toxins. It is an immune reaction caused when the worms that reside in the subcutaneous tissue are injured by a minor or major force to the skin. The insides of the worm are then exposed to the immune system, and a powerful reaction ensues. Normally, the immune system does not detect the helminth until it is injured.