Anti-Seborrheics

ANTI-SEBORRHEICS

These are drugs effective in seborrheic dermatitis which affects areas rich in sebaceous glands (scalp, face, trunk) and is characterized by erythematous, scaling lesions. Dandruff is the commonest complaint. A causal role of the yeast Pityrosporum ovale has been shown, but various trigger factors like change in quantity and composition of sebum, increase in alkalinity of skin (due to increased sweating), external local factors, emotional stress, genetic predisposition appear to be needed to transform the yeast from a commensal to a noninvasive pathogenic organism. Drugs used are:

Selenium sulfide Applied to the scalp as a 2.5% lotion or shampoo, it slows epidermal prolifera tion and scaling. It is also antikeratolytic and fungicidal to P. ovale. Dryness, folliculitis and dandruff are benefited, but > 50% patients relapse on discontinuation. Systemic absorption and toxicity can occur if it is applied to inflamed or damaged skin. Some individuals develop sensitivity reactions.

SELSUN 2.5% susp., SELDRUFF PLUS 2.5% susp. with clotrimazole 1%.

Zinc pyrithione It reduces epidermal turnover and inhibits P. ovale. Weekly shampoo (1%) reduces dandruff, but symptoms do not resolve completely. It is often combined with ketoconazole.

SCALPE: Zinc pyrithione 1%, Ketoconazole 2% shampoo.

Corticosteroids Massaged in the scalp as a lotion, topical steroids are highly effective in relieving symptoms of seborrheic dermatitis including dandruff. Pityrosporal yeasts are reduced in the affected skin. However, relapse rates are high on discontinuation and prolonged use can produce adverse effects like atrophy, poor healing, purpura, etc.

Imidazole Antifungals Among several of these compounds, ketoconazole (KTZ) was found to be the most effective against P. ovale. Orally (200 mg/ day for 4 weeks) it has been found to improve seborrhoea. But because this is often a chronic relapsing condition and prolonged oral KTZ therapy is considered unwarranted, KTZ has been formulated into 2% cream/shampoo/scalp gel. Good to excellent results have been obtained with these preparations without skin irritation, contact sensitivity, phototoxicity or systemic adverse effects.

KETOVATE, NIZRAL, OCONA 2% cream, 2% shampoo.

Clotrimazole 1% solution may be used in its place.

Sulfur, Resorcinol, Coaltar, Ammoniated mercury These drugs are mildly effective. They have minimal antiyeast action: may benefit seborrhoea by keratolytic and antiseptic properties.

Salicylic acid  It is keratolytic, has mild effect in seborrhoea, probably by removing the scales and by improving penetration of other drugs.