Seborrheic dermatitis is a common skin disorder.

What is Seborrheic Dermatitis?
This condition is a red, scaly, itchy rash in various locations on the body. The scalp, sides of the nose, eyebrows, eyelids and the skin behind the ears and middle of the chest are the most common sites. Other areas, such as the navel (belly button) and skin folds under the arms, breasts, groin and buttocks, may also be involved. These areas have the highest concentration of sebaceous glands.

Are Dandruff, Seborrhea and Seborrheic Dermatitis the Same?
Dandruff appears as scaling on the scalp without redness. Seborrhea is oiliness of the skin, especially of the scalp and face, without redness or scaling. Patients with seborrhea may later get seborrheic dermatitis. Seborrheic dermatitis has both redness and scaling.

Who Gets Seborrheic Dermatitis?
This condition is most common in three age groups - infancy, when it's called "cradle cap," middle age, and the elderly. Cradle cap usually clears without treatment by age 8 to 12 months. This may be due to the gradual disappearance of hormones passed from the mother to the child before birth. In some infants, seborrheic dermatitis may develop only in the diaper area where it could be confused with other forms of diaper rash. When seborrheic dermatitis develops at other ages it can come and go.

Seborrheic dermatitis is also common in people with oily skin or hair. It may also be seen in people with acne or psoriasis.

A yeast-like organism may be important in causing seborrheic dermatitis.

Is this Condition Associated with Other Diseases?
Seborrheic dermatitis may occur in patients with other illnesses. There does appear to be more seborrheic dermatitis in adults with disease of the nervous system, such as Parkinson's disease. Patients recovering from stressful medical conditions, such as a heart attack, may also develop this problem. People in hospitals or nursing homes and those with immune system disorders appear to be more prone to this disorder. People with seborrheic dermatitis have no increased risk of other skin diseases. This condition does not progress to or cause skin cancer, no matter how long it remains untreated.

How Long Does this Disease Last?
Seborrheic dermatitis may get better on its own, but it usually improves with treatment. However, it may recur.

Can it be Prevented or Cured?
There is no way to prevent or cure seborrheic dermatitis. However, it can be effectively treated.

Are Laboratory Tests Useful in Diagnosing this Disease?
For most patients, there is no need to perform blood, urine or allergy tests. In rare cases of chronic seborrheic dermatitis that do not respond to treatment, a skin biopsy or other laboratory testing may be done to eliminate the possibility of another disease.

How is this Condition Treated?
This skin disorder is treatable but may recur. Gentle shampooing with a mild shampoo is helpful for infants with cradle cap. A low strength costeroid cream or lotion may also be applied to the affected areas of skin. Adult patients may need to use a medicated shampoo and a stronger costeroid preparation. Nonprescription shampoos containing tar, zinc pyrithione, selenium sulfide, sulfur and/or salicylic acid may be recommended by a dermatologist or a prescription shampoo may be given. However, patients should follow their dermatologist's advice, excessive use of stronger preparations can cause side effects.