Sea lice actually are not lice at all but jellyfish larvae. When trapped under a bathing suit or other clothing, sea lice can cause an irritating skin rash. Sea lice, generally found in warmer waters, are most active between April and August.
Remove your bathing suit and shower thoroughly with warm water. Note: Wash the suit and dry it on high heat before wearing it again.
Apply Topical Treatments
After showering, apply a thin layer of cream, such as an over-the-counter 0.5 hydrocortisone cream or calamine lotion, to the rash. Read and follow label instructions carefully. Dress in fresh, clean clothing.
Antihistamines, such as diphenhydramine, may be a good option. Read and follow all label directions carefully when using antihistamines or any other medication. Do not use antihistamines at the same time as hydrocortisone creams or calamine lotion unless directed by a health care professional.
Soothe the Skin
After an initial shower, bathing in colloidal oatmeal may soothe irritated skin and provide comfort. To avoid further irritation, it's a good idea to clip children's fingernails and discourage scratching.
Some people, especially children, may develop a fever. Consult a doctor if a child's temperature exceeds 101 degrees F.