Cradle CapThese thick, scaly patches of skin that form on a baby's scalp and sometimes on the forehead are common, harmless, and not contagious.
Peak age: 1 month, though it may continue until 6 months.
What to do: It'll disappear on its own, but you may speed the process by washing your baby's hair daily with mild baby shampoo, then toweling it dry. Or use your fingertips to gently rub away the extra layers of skin that form cradle cap. Call the doctor if the condition persists for more than eight weeks, especially if it spreads to the face, neck, and behind the ears; she may recommend a potent medicated shampoo.
Richard Trubo contributes to the American Academy of Pediatrics parenting guides.