Hydrocortisone is an anti-inflammatory and immunosuppressive drug, used in medications designed to soothe redness and reduce swelling from insect bites, allergies, eczema, psoriasis and other inflammatory skin conditions. Considered a mild corticosteroid (a class of drugs called steroids), it prevents the release of substances in the body that cause inflammation and is considered safe for short term use on the skin. Long term use (daily for months) can lead to thinning of the skin.