Dermatitis is an inflammation of the skin that makes it red, swollen, and itchy. There are many types, including allergic and irritant contact dermatitis, atopic dermatitis (eczema), and seborrheic dermatitis (dandruff). It affects people of all ages but often begins in childhood. Symptoms include a red rash, blisters, dry cracked skin, itching, pain, swelling, and flaking. Treatment depends on the type but may include moisturizers, topical corticosteroids, oral antibiotics, and lifestyle changes to avoid irritants.