MODEL RELEASED. Cradle cap. Newborn baby with cradle cap (crusta lactea). Thick yellow scales are seen in patches around the infant's scalp. Cradle cap is a form of seborrhoeic dermatitis: an itchy,flaky rash of unknown cause. It is common in babies and usually harmless, unless the affected skin becomes infected. Treatment includes regular washing and applying warm olive oil or arachis oil to the scalp to loosen the scales. If the inflamation worsens or infection develops, corticosteroid drugs and antibiotics may be needed.