When you have a newborn, you may expect diaper rash and cradle cap. But what about those white bumps across your baby's nose and chin? Or the red bumps on your baby's cheeks? These complexion problems are known as milia and baby acne. They're not pretty, but they're common — and temporary.

Milia are pearly white bumps on a baby's nose, chin or cheeks. Sometimes milia affect a baby's gums or roof of the mouth as well. Baby acne is more pronounced. You may notice small red or white bumps on your baby's forehead or cheeks. Baby acne may look worse when your baby is fussy or crying.

Many babies are born with milia. Baby acne often develops within the first three to four weeks after birth. Many babies have both conditions at once.

Milia occur when tiny skin flakes become trapped in small pockets near the surface of your baby's skin. Baby acne is related to hormonal changes that stimulate oil glands in the skin. Milia affect boys and girls equally, but baby acne is more common in boys. Rarely, baby acne is a sign of a hormonal problem.

Most cases of milia disappear on their own within several weeks. Baby acne often clears up quickly, too. In some cases, however, baby acne lingers for months or even longer.

In the meantime, wash your baby's face with warm water two or three times a day and pat it dry. Don't use lotions, oils or other treatments. Never pinch or scrub milia or baby acne. You may cause more irritation or an infection.

If you're concerned about your baby's complexion or it doesn't clear up within three months, consult your baby's doctor. He or she may recommend a medicated cream or other treatment.

There's little you can do to prevent milia or baby acne. Simply wash your baby's face with water and look forward to the clearer days ahead.