DANDRUFF AND SEBORRHOEIC DERMATITIS

Dandruff is a common scalp condition in which small pieces of dry skin flake off from the scalp and is usually associated with itching. Dandruff is considered to be a mild form of an inflammatory disorder of the skin called "Seborrhoeic Dermatitis”.

Dandruff typically affects the scalp only and is a mild form with loose adherent flaking.
Seborrhoeic Dermatitis can extend beyond the scalp and it affects ears, eyebrows, the folds beside the nose, beard area, upper back and chest.
Redness and itching of the skin is seen along with flaking which may be dry or yellowish and greasy in nature.

The exact cause of Dandruff and Seborrhoeic Dermatitis is unknown.

The exact cause that leads to Dandruff and Seborrhoeic Dermatitis is unknown. Possible causes include increased oil production and secretion, increased numbers of normal skin yeasts and a genetic predisposition.
Common triggers (factors that may worsen) include oily skin or scalp, emotional stress, weather (cold and dry), poor hygiene and infrequent washing or shampooing. Dietary factors do not play a role.
Seborrhoeic Dermatitis is also seen more often and severely in HIV infection and Parkinson’s disease patients.

Seborrhoeic Dermatitis commonly manifests in adolescence or adulthood. However it can also be seen in children as a “cradle cap” on the scalp or as a rash in the nappy area.

Seborrhoeic Dermatitis can manifest in the form of itchy flaking skin or the rash may be present without any symptoms. It can have varied appearances such as:

• Itchy scalp
• White flakes on shoulders of dark clothing
• Scaly facial skin
• Facial rash over eyebrows, nose, and ears
• Recurrent ear eczema-itchy flaky skin or oozing in the ear canal
• Oily scalp and facial skin with dry flakes
• Eyebrow or beard rash
• Rash on the trunk ( mid-chest or mid-back)-dry flakes and red spots
• Rash in the skin folds (armpits, groins, under the breast)-redness/scaling

Seborrhoeic Dermatitis has a genetic predisposition and can often be seen amongst family members.
Seborrhoeic Dermatitis is not contagious and it cannot be transmitted to contacts or family members.

Seborrhoeic Dermatitis is diagnosed by its clinical appearance and behaviour.
As some fungi are naturally present on our skin, its presence on microscopy of skin scrapings is not diagnostic.

Diagnosis of Seborrhoeic Dermatitis is chiefly based on history and clinical examination. There are no conclusive laboratory tests that can diagnose Seborrhoeic Dermatitis. Skin scrapings and biopsy are done to rule out other conditions which can resemble Seborrhoeic Dermatitis (ringworms, psoriasis)

Different types of shampoos may be prescribed for Dandruff. These include:

• Tar-based shampoo
• Ketoconazole based shampoo
• Zinc pyrithione based shampoos
• Selenium sulphide based shampoo
• Ciclopirox based shampoos

Shampoos should be used at least twice a week for 3 to 4 weeks. The shampoo needs to be left on for 5 to 7 minutes after application in order to ensure adequate time for action. All affected areas and the chest should also be washed with the therapeutic shampoo.

The treatment options include anti-dandruff shampoos, cleansers, anti-inflammatory creams/lotions, antifungals and keratolytics.

Mild topical corticosteroids, preferably in lotion form are prescribed for 1-3 weeks to reduce inflammation. Cream based topical steroids may be used for treating the affected areas of the face, ears, and eyebrows.

Topical calcineurin inhibitors such as pimecrolimus cream can be used instead of topical steroids.

Topical antifungals such as ketoconazole, clotrimazole can be used or combined with mild topical steroids. Oral antifungals are indicated in severe cases.

Keratolytics can be used to remove scales when necessary, for eg. Salicylic acid, lactic acid, urea, propylene glycol.

The choice of treatment depends on the sites affected, and the extent of symptoms. Maintenance treatment is usually needed.

Seborrhoeic Dermatitis may improve with treatment, but there is no known permanent cure.

Increased sebum production is an individual tendency and can recur. Those who have a tendency to develop Seborrhoeic Dermatitis recurrently require re-treatment at frequent intervals.