Seborrhoeic dermatitis is commonly known as “cradle cap”. This condition is very common in young infants. The exact etiology is unknown. The infants will presents with distinctive greasy, scaly, erythematous rash or plaques. The crusty scales usually appear within the first year of life, particularly the first few months of life. The common affected sites are eyebrows, skin behind the ears (retroauricular) and perineum. Other common sites are nasolabial (area between the mouth and the nose) and axillary (under the armpit) area. This lesion may persist into adolescence and it will present with severe dandruff and skin changes (marginal blepharitis). Common parts are the medial aspect of the eyelids and the external auditory canals.
Sporadically, some discoid lesions can be found spreading up to the trunk from a napkin rash. This condition is known as napkin psoriasis. Seborrhoeic dermatitis can be misdiagnosed with atopic eczema, particularly if the rashes are found over flexures area. Rarely, the disease will be widespread to the other parts of the body and it is known as Leiner syndrome. However, cradle cap is only a benign condition and never involves any systemic illness. On the other hand, secondary infection may occur.
Treatment is by using olive oil to soften the scales. Subsequently, hair needs to be comb to remove the scales. Sometimes, mild corticosteroid cream such as 1% hydrocortisone will be prescribed. Cradle cap usually responds to a keratolytic shampoo (containing selenium) or cream, but often recurs. In evidence of secondary antibiotics, antibiotics, either oral or topical will be given depending on the severity of the disease. In a condition where the response to treatment is poor, ones should consider other diagnosis likes psoriasis and fungal infection. Rare causes of crusty scales of the scalp are HIV infection and Langerhan’s cell histiocytosis.
Reference:
- David Candy et al. Clinical Paediatrics and Child Health. W.B. Saunders. 2001.
- Alan Cade et al. Short Cases in Paediatrics. Greenwich Medical Media Limited. 2000.
- Paediatrics Colour Guide.
