Hydrocortisone Cream Packets relieve minor skin irritations, itching, and rashes caused by insect bites, dermatitis, eczema, allergies to detergents or soaps, and poison ivy. Hydrocortisone cream is a topical corticosteroid that works by reducing skin inflammation (itching, redness, swelling, and irritation). To use Hydrocortisone, apply a small amount of cream to the affected area then gently rub it in evenly then leave the area open and not bandaged.