Cradle Cap

Cradle cap is infantile seborrhoeic dermatitis of the scalp, with greasy, yellow, scaly crusted patches on the scalp of infants. Very common, affecting about 10 percent of infants in the first 3 months.

• Onset in the first 2 to 12 weeks (peak at 3 weeks to 3 months), resolves in weeks to months, usually by 6 to 12 months.
• Cause is unknown; associated with maternal hormones increasing sebum production, Malassezia yeast overgrowth, altered skin barrier; not caused by poor hygiene, allergy or infection and is not contagious.
• May extend to eyebrows, ears, face, neck, nappy area and flexures (infantile seborrhoeic dermatitis).
• Persistent or severe forms overlap with atopic dermatitis and psoriasis.

• Thick, adherent, greasy, yellow white or brown scales and crusts on the scalp (vertex and frontal) ranging from mild flaking to confluent plaques, with underlying pink skin; minimally itchy; the infant is well and feeding.
• Possible mild redness behind the ears, in the neck folds, on the eyebrows and in the nappy area.
• Red flags (alternative diagnosis): marked inflammation or weeping, widespread scaling, severe itch with sleep disturbance (atopic dermatitis), haemorrhagic crusted papules and erosions in flexures, scalp ulceration, hair loss (tinea capitis, Langerhans cell histiocytosis), failure to thrive or diarrhoea (immune deficiency, zinc deficiency, Leiner disease), pustules and fever (bacterial infection), onset after 6 months, family history of psoriasis, lymphadenopathy, hepatosplenomegaly, otitis media or diabetes insipidus (Langerhans cell histiocytosis).

• Clinical diagnosis from the characteristic appearance in a well infant.
• Skin scraping for fungal microscopy and culture if hair loss, inflammation or scaling suggests tinea capitis; bacterial swab for suspected infection; skin biopsy for atypical lesions (Langerhans cell histiocytosis).
• Differentials: atopic dermatitis, psoriasis (infantile), tinea capitis, impetigo, head lice, Langerhans cell histiocytosis, Leiner disease, zinc deficiency, scabies.

• Reassure that cradle cap is harmless, usually clears by itself, and is not a sign of poor hygiene or allergy.
• Mild: wash the scalp with a mild baby shampoo 2 to 3 times a week and gently brush with a soft brush or comb to loosen scales.
• Softening scales: massage a liberal amount of white soft paraffin, mineral oil, emollient or olive oil (or coconut oil) into the scalp, leave for 1 to 2 hours or overnight (avoid peanut or arachis oil because of allergy risk), then gently brush and shampoo; repeat daily until scales lift; do not pick or scrape.
• Persistent or inflamed cradle cap:
  • Ketoconazole 2 percent shampoo applied to the scalp twice weekly for 2 to 4 weeks, left on for 5 minutes then rinsed (avoid contact with eyes).
  • Hydrocortisone 1 percent cream or ointment applied thinly once or twice daily for 3 to 5 days on inflamed areas of scalp, face and flexures; avoid prolonged use.
  • Miconazole 2 percent or clotrimazole 1 percent cream twice daily for 1 to 2 weeks for facial, flexural or nappy area involvement (suspected Candida).
• Avoid salicylic acid preparations in infants (absorption and toxicity).
• Treat secondary bacterial infection with mupirocin 2 percent ointment three times daily for 5 days.
• Resolution generally takes weeks to months; relapses may occur.
• Refer to a paediatrician or dermatologist for persistent, extensive, treatment resistant disease, failure to thrive, or red flag features.