Infantile seborrhoeic dermatitis

• presenting within the first few months postpartum as cradle cap or napkin dermatitis. It sometimes spreads widely via the flexures.
• most cases eventually resolve spontaneously within weeks to a few months.  Cases persisting beyond the age of 12 months are rare
• Seborrhoeic dermatitis appears to be an inflammatory response to malassezia yeasts, which proliferate in oily skin (seborrhoea).
• In infants it is supposed that maternal androgens are responsible.
• Characteristically, the scale is yellowish and greasy or white and bran-like (pityriasiform) associated with variable nummular or annular pale pink to bright red patches.
• Itching tends to be absent or mild.

Treatment

• In infants, seborrheic dermatitis has a self-limited course and resolves spontaneously in weeks to several months.
• suggest that initial treatment should be conservative, including education and reassurance of parents, and simple skin care measures
• Application of an emollient (white petrolatum, vegetable oil, mineral oil, baby oil) to the scalp (overnight, if necessary) to loosen the scales, followed by removal of scales with a soft brush (eg, a soft toothbrush) or fine-tooth comb
• Frequent shampooing with mild, non-medicated baby shampoo followed by removal of scales with a soft brush (eg, a soft toothbrush) or fine-tooth comb

Extensive/Persistent Cases

• a short course of low-potency topical corticosteroids applied once per day for one week
• Corticosteroids are preferred if there is a predominant inflammatory component
• ketoconazole 2% cream or shampoo twice per week for two weeks
• ketoconazole 2% cream or shampoo is an alternative in diffuse cases or if the use of topical corticosteroids is a concern for the parents.

Non-scalp seborrheic dermatitis

• ketoconazole 2% cream (once a day for one to two weeks) or a low potency topical corticosteroid (eg, hydrocortisone 1% cream once a day)
• topical corticosteroids should be limited to the time needed to achieve the clearing of the lesions, but no longer than one week
• In addition, emolients, topical creams or ointments containing zinc oxide and/or petrolatum may be applied liberally

Other Treatments

• selenium sulfide 2.5%, zinc pyrithione, salicylic acid
• no clinical trials evaluating their efficacy and safety in infants.
• shampoos and ointments containing salicylic acid
• may result in systemic toxicity because of transcutaneous absorption

Evidence

• no randomized trials of antifungal agents or topical corticosteroids for the treatment of cradle cap in infants
• All the studies indicated that the two treatments (topical antifungals and topical corticosteroids)were equally effective
• use of lower potency topical corticosteroids in children is generally safe when used for short durations.
• If the rash does not resolve after one week of corticosteroid therapy or two weeks of antifungal therapy as described above, the diagnosis should be reconsidered

References:

1. www.uptodate.com
2. http://www.aafp.org/afp/2006/0701/p125.html
3. http://www.dermnetnz.org/doctors/dermatitis/seborrhoeic.html