Seabather's eruption

Seabather's eruption is a pruritic dermatitis caused by a hypersensitivity reaction to the immature nematocysts of larval-stage thimble jellyfish (Linuche unguiculata), sea anemones (Edwardsiella lineata) and other larval cnidarians.

It should not be confused with Swimmer's itch. However, the term "sea lice" is also sometimes used to describe Seabather's eruption.