Seborrheic dermatitis is a skin condition that causes flaky scales to form on the scalp or in the ears though it can form on any part of the body where the skin produces excess oil. Some people also have redness and inflammation of the skin. When infants acquire the condition it is called cradle cap and normally clears up before the child's first birthday. The term seborrheic dermatitis is often used interchangeably with the term dandruff. Dandruff is a form of seborrheic dermatitis that occurs without redness.
The exact cause of seborrheic dermatitis isn't known but it is believed to be influenced by the presence of a fungus called Malassezia. Malassezia is normally present in the oil secreted by the skin but excess amounts disrupt the balance of the skin and cause scales to form. Some people find their symptoms are worse in the winter when the air is cold and dry. Those with neurological disorders like Parkinson's disease have a high incidence of seborrheic dermatitis though scientists have not discovered why. Unlike many other conditions caused by fungus, seborrheic dermatitis is not contagious.
Seborrheic dermatitis is similar to other skin conditions such as psoriasis, eczema, and ringworm, so the doctor may take a skin biopsy for microscopic analysis to verify the diagnosis. Once diagnosed the doctor will advise the patient on what products to use to control the fungus and reduce inflammation and scaling. This first line of treatment is the use of topical antifungal ointments and shampoos on the scalp. Most are available over-the-counter but especially difficult cases may require prescription-strength medications. Lamisil is a prescription oral antifungal that is used in severe cases but its use is limited due to serious side effects. Steroid creams are beneficial in the reduction of inflammation and itching but can only be used short term due to their tendency to damage the skin and lower the body's immune response.