Petaloid Seborrheic Dermatitis

Petaloid seborrheic dermatitis is a type of seborrheic dermatitis that occurs in people with dark skin. They are present with red, scaly plaques in the eyebrows, around the hairline, and along the Melo-labial fold. It also comes in the form of polycyclic coalescing rings. These rings may be hypopigmented in colour or pink and usually won’t show significant scale until the area is scraped for a potassium hydroxide (KOH) preparation.

Petaloid seborrheic dermatitis has been associated with the yeast Pityrosporum orbiculare, the mite Demodex folliculorum, various bacterial colonization, and skin response to the environment, such as changes in humidity, temperature, and bath water.

Treatment usually includes the application of a topical corticosteroid containing 1% hydrocortisone cream. In complicated cases, 0.2% hydrocortisone valerate or 0.5% desonide creams may be applied twice daily. Use of stronger corticosteroids on areas other than the scalp is discouraged as it may lead to telangiectases, atrophy, perioral dermatitis, and, in people with dark skin, noticeable hypopigmentation. Topical and systemic anti-fungal agents are also good.

Shampoos containing ketoconazole can help many people with petaloid seborrheic dermatitis. Washing the hair and the face with prescription and over-the-counter dandruff shampoos containing selenium sulfide, zinc, and sulfur may also help as these are very gentle on the skin.

Oral itraconazole is another treatment that can help with petaloid seborrheic dermatitis.