Seborrheic Dermatitis
Seborrheic dermatitis is a skin condition which can affect anyone including babies. It therefore becomes essential that one takes timely treatment in order to control it. Dr Shefali Trasi Nerurkar, a skin specialist, lists down points you need to know to keep this condition in check.
Seborrheic dermatitis (SD) is a common, chronic, relapsing inflammatory skin disorder clinically characterised by ill-defined flaky, white to yellowish scales with or without reddened skin. It primarily affects oily areas, including scalp, face, upper chest, back and flexors. It is more prevalent among males but usually occurs in infants within the first three months of life.
Types
Infantile: In infants, it appears as pinkish, flaky patches on areas such as the face, limbs, trunk, armpits, groin, etc but the most common occurrence is as a cradle cap on the scalp. Infantile seborrheic dermatitis is non-itchy and in most cases clears up by the age of six months.
Adolescent and adult: Seborrheic dermatitis can occur on different body areas where the skin is oily or greasy. Common areas include the scalp, eyebrows, eyelids, creases of the nose, lips, behind the ears, in the outer ear, and middle of the chest.
On the scalp, it occurs in the form of dandruff which is essentially an uninflamed form the condition. Dandruff can extend to non-hairy areas as well if the condition worsens.
Causes
The exact cause of seborrheic dermatitis is unknown. Excessive secretion of sebum which is called seborrhea is a predisposing factor but not a primary cause.
The skin condition is believed to be caused by yeast called Malassezia due to the skin’s inflammatory reaction to its proliferation or growth. Interaction of this yeast with the oil glands elicits an inflammatory skin response in individuals thus irritating the skin. Patients with seborrheic dermatitis appear to have a reduced resistance to the yeast.
The condition can also be aggravated by factors such as stress, fatigue, general illness, change in the weather, especially during winters. But it is not related to one’s diet neither is it contagious.
People with disorders such as Parkinson’s disease, stroke, immunodeficiency, heavy drinkers are prone to seborrheic dermatitis.
Diagnosis
The diagnosis of this skin condition is based on the appearance and location of the skin lesions. No tests are normally necessary and a skin biopsy is seldom needed. If there is any suspicion of scalp ringworm (a fungus infection), KOH mount, culture from scales can be considered.
Treatment
Treatments only suppress seborrheic dermatitis rather than cure it. Hence, it often comes back after the treatment has stopped. Therefore, continuous or periodical treatment is required for months or even years. The condition can generally be kept under control with regular use of antifungal agents and intermittent application of topical steroids. The choice of treatment also depends on which part of the skin is affected by it. Here are some of the possible treatment options.
For infantile seborrheic dermatitis
Emollients such as mineral oil, petrolatum, olive oil, Ketoconazole 2% cream/shampoo, tar based shampoos, low potency topical steroid and in unresponsive cases, systemic fluconazole are the main treatment options.
For seborrheic dermatitis in adults
a. Scalp (Dandruff)
For flaky scalp, medicated shampoos containing agents such as zinc pyrithione, selenium sulphide, ciclopirox olamine, piroctone olamine shampoos, climbazole, miconazole, clotrimazole or ketoconazole are usually prescribed.
Sometimes, a scalp application containing a steroid, used sparingly and occasionally can help by reducing itching and redness. Alternatively, a salicylic acid 3%, 6% based ointment can be rubbed on the scalp at night and washed off in the morning with keratolytics like shampoo.
b. Rest of the body
Mild steroid creams and/or an antifungal component are usually effective. Commonly preferred steroids are betamethasone, fluocinolone acetonide, sesonide, and hydrocortisone. In severe cases, clobetasol, mometasone, fluticasone can be used. Washing your body with an antifungal shampoo containing ketoconazole may also help.
Occasionally, if the rash is widespread or resistant to these treatments, a short course of an oral anti-yeast medication is required. Recently, creams classified as topical immune modulators (Pimecrolimus 1% cream, Tacrolimus 0.03%, 0.1% cream) are being used. This medicine suppresses the immune system to treat inflammation. In severe cases, course of systemic antifungals like ketoconazole, itraconazole, terbinafine, fluconazole are needed. Short course steroids treatment for generalised/severe involvement is usually required.
It is believed that sunlight improves the condition. In some people, the condition gets better in the summer, especially after outdoor activities. Hence, phototherapy (or light therapy) is one of the treatment options.
Prognosis
Seborrheic dermatitis is a chronic condition and can only be controlled with treatments. Its severity can be decreased by taking care of one’s skin and controlling risk factors which aggravate the condition further.
Complications
The possible complications of seborrheic dermatitis
- Psychological distress
- Low self-esteem, embarrassment
- Secondary bacterial or fungal infections
The content has been verified by
Dr Shefali Trasi Nerurkar
, skin specialist.
91 – 22 – 2490 0302.