What Are Different Types of Dermatitis?
Reviewed by: HU Medical Review Board | June 2017 | Last updated: September 2020
Dermatitis is a general term that means inflammation of the skin. Dermatitis is also commonly referred to as eczema, which is also a general term for skin inflammation. There are several different types of dermatitis that are caused by infections, allergies, or substances that irritate the skin. A doctor can diagnose which type of dermatitis is present and provide the appropriate treatment strategies.
Atopic dermatitis is a chronic skin condition that is commonly seen in families. It usually begins in early childhood. Many people outgrow the condition by adulthood, although some people continue to have flare-ups as adults.
What are the symptoms of atopic dermatitis?
Atopic dermatitis causes dry, extremely itchy, inflamed patches that are sometimes scaly. The patches can become infected with scratching. Atopic dermatitis may worsen when the skin comes in contact with irritating substances, including some harsh soaps or tight clothing. With repeated flare-ups and chronic scratching, atopic dermatitis can lead to thickening of the skin, causing leathery patches that are constantly itchy.
Where does atopic dermatitis occur?
In babies, atopic dermatitis can appear as a rash on the cheeks, outer surfaces of the elbows or knees, or the scalp. In children, the condition may show up in the creases of the elbows or knees, or on the neck, wrists or ankles. In adults, atopic dermatitis also appears in the creases of elbows and knees, as well as the nape of the neck or the face.1,2
Contact dermatitis encompasses both irritant contact dermatitis and allergic contact dermatitis.
What is irritant contact dermatitis?
Irritant contact dermatitis is a reaction that occurs when the skin comes in contact with a substance that is irritating, such as detergents, soaps, cleaners, or other chemicals.
What is allergic contact dermatitis?
Sometimes, the skin develops an allergy to a substance that comes into contact with it; this is called allergic contact dermatitis. An allergy can develop after one or several exposures to a substance. Common causes of allergic contact dermatitis include cosmetics, adhesives, or metals. A frequent contributor to allergic contact dermatitis is nickel. Many people have an allergic reaction to nickel, which is commonly used in inexpensive jewelry, earrings, zippers on clothing, or eyeglass frames.2,3 Contact dermatitis can cause mild swelling of the skin, dry or cracking skin, blisters that ooze, painful ulcers, reddening, and itching of the skin.2
Dyshidrotic eczema (pompholyx)
Dyshidrotic eczema is also called pompholyx or vesicular eczema. Dyshidrotic eczema forms small, itchy, fluid-filled blisters on the fingers, toes, palms of the hands, and soles of the feet and is often a manifestation of other types of eczema, such as atopic dermatitis and contact dermatitis. Dyshidrotic eczema also causes redness of the skin and may be painful. Several factors can trigger dyshidrotic eczema, such as stress, allergies, moist hands and feet, or contact with irritants, including nickel, cobalt, or chromium salts.4
Hand eczema is caused by both genetic and environmental factors, such as contact with irritating chemicals or allergens. Hand eczema appears on the hands as redness, itching, pain, dryness, blisters, and cracks in the skin, and is often a manifestation of an underlying condition like atopic dermatitis or contact dermatitis.4
Neurodermatitis is similar to atopic dermatitis, as it appears as thick, scaly patches on the skin due to rubbing or scratching of the area. Also known as lichen simplex chronicus, neurodermatitis frequently appears on the nape of the neck, scalp, shoulder, ankles, wrists, backs of the hands, or the feet. The skin affected by neurodermatitis may often be discolored.4
Nummular eczema has a distinct appearance from other forms of dermatitis, producing coin-shaped spots on the skin that are frequently itchy. The skin affected by nummular eczema may also be dry and scaly. Also known as discoid eczema, it is believed that insect bites, dry skin during the winter, or other skin inflammations may cause the condition.4
Seborrheic dermatitis, or seborrheic eczema, appears as a rash on areas of the body with a lot of oil-producing glands, including the scalp, upper back, and nose. Seborrheic dermatitis can cause redness, itchiness, greasy skin, crusty or flaky skin, or swelling. Seborrheic dermatitis is believed to be caused by genetic factors, hormones, and the microorganisms that live on the skin.4
Follicular eczema is considered to be a variation of atopic dermatitis and is frequently seen in people with darker skin. Follicular eczema affects the hair follicles, and typically causes small red bumps and itching on the back, arms, and upper thighs. Like other forms of eczema, it is a chronic condition that is triggered by stress, poor diet, changes in the weather, or allergies.5
Dermatitis herpetiformis creates an extremely itchy rash that is characterized by bumps and blisters. It often appears on the extensor elbows and knees, back, and buttocks. Dermatitis herpetiformis is a chronic condition and has a strong association with celiac disease, the autoimmune disorder that causes inflammation in the intestines when the person eats gluten. In people with dermatitis herpetiformis, eating gluten causes a skin rash, and treatment of the condition usually entails gluten restriction.6