Dermatitis is a common condition that describes inflammation of the skin. There are several forms of dermatitis but usually the condition leads to itching, pain and a skin rash that may be formed of blisters or red, swollen bumps.
Some of the different types of dermatitis include:
Also called eczema, atopic dermatitis is one of the most common forms of dermatitis. The condition usually develops during childhood and affects almost 10 to 20% of children in developed countries, compared with only 1 to 3% of adults.
Atopic dermatitis has become almost three times as common in the US over the last three or four decades. The condition leads to dry, red and itchy skin that may crack, ooze fluid and form crusts. This can lead to scarred and thickened skin in affected areas.
Contact dermatitis refers to a skin reaction that occurs on contact with a particular substance. The substance may be either an irritant that causes physical damage to the skin or an allergen that triggers an immune response leading to skin symptoms.
Irritant contact dermatitis is much more common than allergic contact dermatitis, with irritants accounting for 80% of contact dermatitis cases. Some examples of substances that trigger contact dermatitis include soaps, detergents, metals, cosmetics, jewellery, perfumes, latex, rubber, certain topical medications and plants such as poison ivy.
Dermatitis herpetiformis leads to painful and itchy red lesions that resemble those observed in herpes infection. It is caused by an intolerance to gluten.
Seborrheic dermatitis is a condition that commonly leads to greasy, itchy, flaking deposits of skin across the scalp, ears and nose. In newborn babies, the condition is termed cradle cap.
Stasis dermatitis is seen in people with varicose veins where the return of venous blood from the legs is impaired, leading to pooling of blood in the lower limbs.
Nummular dermatitis often occurs after a skin injury caused by a burn, abrasion or insect bite and is typically characterized by itchy and uncomfortable coin-shaped sores on the skin.
Neurodermatitis is an intensely itchy skin condition caused by irritation of the nerve endings under the skin. Repeated scratching of the area can eventually lead to thick and leathery looking skin.
Perioral dermatitis describes a rash formed of small, red, itchy bumps that occurs around the mouth. The condition mainly affects women and may arise as a result of using cosmetics, dental products containing fluoride or topical corticosteroids.
Reviewed by Sally Robertson, BSc