“Dermatitis” simply means inflammation of skin. There are several types of dermatitis, including allergic contact, atopic, perioral, and seborrheic dermatitis.
What is Allergic Contact Dermatitis?
Allergic contact dermatitis is caused by your body’s reaction to something that directly contacts the skin. Many different substances, or allergens, can cause allergic contact dermatitis, including nickel, rubber (latex), dyes, poison ivy, and poison oak. Allergens typically cause no trouble for most people. But once the skin becomes sensitive or allergic to the substance, any exposure will produce a rash. The rash usually doesn’t start until a day or two later, but can start as soon as hours or as late as a week.
Allergic contact dermatitis usually shows redness, swelling and water blisters ranging from tiny to large. The blisters may break, forming crusts and scales. Untreated, the skin may darken and become leathery and cracked. Allergic contact dermatitis can be difficult to distinguish from other rashes, especially after it has been present for a while.
To treat allergic contact dermatitis, you and your dermatologist will discuss the materials that have touched your skin at work and home to try to identify the allergen. Your dermatologist may also perform patch tests. Patch testing is a safe and relatively quick way to diagnose contact allergies. A small amount of the suspected allergen is applied to the skin for a fixed time, usually two days.
What is Atopic Dermatitis?
Atopic dermatitis, commonly called eczema, is a particular type of skin inflammation that is marked by dryness, associated itching, and a characteristic pattern of rash on the body. The condition is fairly common, and may occur in as many as 10% of children.
The exact cause of atopic dermatitis is unknown. In many patients, there is a family history of hay fever, asthma or atopic dermatitis itself. Rarely, atopic dermatitis in infants may be related to food sensitivity, such as sensitivity to milk, but this is often difficult to determine and manage. In the majority of cases, however, no allergic triggers can be found.
Atopic dermatitis usually starts in infancy from the ages of two to six months. The skin is dry and the rash is quite itchy, so infants may be restless and rub against the sheets, or scratch if able. The rash may involve the face or it may cover a large part of the body. As the child gets older, the rash may become more localized. In early childhood, the rash is commonly on the legs, feet, hands and arms. As a person becomes older, the rash may be limited to the bend of the elbows, knees, on the back of the hands, feet, and on the neck and face. As the rash becomes more established, the dry itchy skin may become thickened, leathery and sometimes darker in coloration. The more the person scratches, the worse the rash is and the thicker the skin gets. Many children with atopic dermatitis outgrow the condition before school age; some continue to have problems as an adolescent or even as an adult.
Many things may affect the severity of the condition. All patients have sensitive and dry skin. Many will find that during the winter months when the humidity is very low, the dryness and itchiness will be worse. On the other hand, some people are easily irritated by sweat and will find that they have more problems during the summer months. Most patients note an increase in itching at times when there are sudden changes in temperature. Other irritants easily affect the skin of a patient with atopic dermatitis. Use of harsh soaps and detergents and exposure to wool are common problems. Sometimes atopic dermatitis may become infected by bacteria, yeast, or viruses. This is called “secondary infection.” Bacterial secondary infection is the most common, and often occurs as the result of scratching. The rash gets very red with pus-filled pimples and scabs. If this occurs, your doctor will prescribe an antibiotic to control the infection. A more serious complication can be caused by certain viruses.
The “cold sore” virus (herpes simplex) may cause a severe rash. If this is suspected, immediately contact your doctor. The virus that causes molluscum also tends to spread rapidly in patients with atopic dermatitis.
Unfortunately, there is no treatment that will always eliminate atopic dermatitis. The main objective in treating atopic dermatitis is to decrease the skin eruption and relieve the itching. There are a number of different forms of medication that are used for atopic dermatitis, and medications that are best suited to control the problem will be chosen. Primarily “topical medications” (medications that are applied to the skin) will be used. Because the skin is usually excessively dry, lubricants will be prescribed that will effectively decrease the dryness. If a soap is tolerated, it should be one that is superfatted to minimize the dryness effect of the soap. Bathing is a useful way to get water into the skin, but bathing should be brief (no more than 10 minutes).
Effective lubricants can be used in conjunction with the bath or shower to trap moisture within the skin. Cortisone derived ointments or creams and newer nonsteroidal ointments or creams may also be suggested, and are very important in decreasing the itching and controlling the inflammation. Your doctor will suggest a treatment that is most appropriate for the severity and location of the dermatitis that is to be treated. When the area is clear, it is best to discontinue the use of the cortisone or nonsteroidal preparation, but continue the vigorous use of lubrication to try to prevent new areas of dermatitis from occurring. Of course, if itching or a new rash begins, the cortisone or nonsteroidal preparation may have to be reintroduced.
Certain internal medicines, called “antihistamines”, may help to control itching. They primarily help with the itching by introducing some drowsiness and allowing the child to sleep at night. Some systemic antibiotics are often useful as well for controlling the secondary infection, and often enable infected dermatitis to be controlled.
What is Perioral Dermatitis?
Perioral dermatitis is a skin disorder characterized by tiny red papules (bumps) around the mouth that most commonly affects young women. While the exact cause is unknown, it may appear after topical steroids are applied to the face to treat other conditions. Perioral dermatitis is usually characterized by an uncomfortable burning sensation around the mouth. Itching is not a common symptom. Most often, patients are primarily concerned with the cosmetic appearance of skin lesions. Rarely, a similar rash may appear around the eyes, nose, or forehead.
Perioral dermatitis is a difficult condition to treat effectively, often requiring several months of treatment. Generally, steroid creams should not be used to treat perioral dermatitis. Your physician may choose to treat these lesions with other topical medications, such as metronidazole, erythromycin, benzoyl peroxide, tacrolimus, or pimecrolimus. In more severe cases, oral antibiotics (such as tetracycline, doxycycline, minocycline, or erythromycin) may be required.
What is Seborrheic Dermatitis?
Seborrheic dermatitis is a common scaling rash that occurs in infants, teenagers and adults. Dandruff is seborrheic dermatitis of the scalp. Seborrheic dermatitis may also occur on the eyebrows, eyelid edges, ears, the skin near the nose, and such skin fold areas as the armpits and groin.
The cause of seborrheic dermatitis is not known, although recently investigators have suggested an overgrowth of yeast is to blame. Seborrheic dermatitis is not related to diet and is not contagious. Stress and physical illness tend to worsen seborrheic dermatitis, but do not cause it. Seborrheic dermatitis often disappears in infants by one year of age. It is common in teenagers and especially in adults; seborrheic dermatitis may get better or worse without any apparent reason.
There is no cure for seborrheic dermatitis; however, the problem can be kept under control. The treatment of seborrheic dermatitis depends on what part of the body is involved. Dandruff (seborrheic dermatitis of the scalp) can usually be controlled by washing the hair often with medicated shampoos as directed by your physician. Sometimes it is also necessary to use solutions or salves containing cortisone. In areas of smooth skin, such as the face and ears, cortisone-containing creams, lotions or ointments can help. Anti-yeast medications can also be used.
Once seborrheic dermatitis is under control, gradually use the medicine less and less. It may even be possible to stop the medicine completely, but usually occasional treatment is needed. If the seborrheic dermatitis is not controlled by the treatment prescribed, please return to the doctor for further evaluation.