What is seabather's eruption?

Seabather’s eruption is an itchy rash caused by the jellyfish larvae, also known as sea lice. The rash occurs when larvae remain trapped under a bathing suit and/or long hair; these small larvae then fire toxins into the skin and, as a result, the rash often develops between four and 24 hours of exposure. Nausea and vomiting may be present with Seabather’s eruption. Treatment requires 1% hydrocortisone cream which usually clears up the affected area within a week.