Rashes are extremely common in infants but the vast majority are harmless and go away on their own. Some, however, may need work-up or can be a sign of a more serious internal diseases or infections. During the first four weeks of life particularly, a newborn’s skin can exhibit a variety of changes. Whether harmless or serious, all of these skin changes can make new parents very anxious and may result in a visit to the pediatrician. This article is an overview of the most common rashes. It does not include information about cradle cap, which can be found here. I hope that it will provide you some guidance about when you should be concerned and when you can breath easily.
Cutis marmorata is a net-like color change of the skin that symmetrically involves the trunk and the limbs. It is caused by constriction of blood vessels in the skin in response to the cold and usually resolves with warming. It often resolves after the first year of life, however it can occasionally last into adulthood. It is totally harmless and no treatment is required.
Harlequin Color Change
Harlequin color change occurs when your newborn lies on their side. It presents with redness on the side of the body where the pressure is applied and blanching (or turning white) of the opposite side at the same time. The color change develops very quickly and lasts between 1 minute and 1 hour. It completely resolves when your baby starts moving around or crying. One in ten newborns are affected, but you may not notice it because your baby is all swaddled up. It most often occurs in the first week of life but can persist up to about one month. Harlequin color change is probably related to a newborn’s brain immaturity and its lack of experience relaxing and constricting the blood vessels in their skin.
Erythema Toxicum Neonatorum
Erythema toxicum neonatorum (a really long, scary name, I know!) is the most common pustular eruption in infants. Pustular just means containing pus, like in a big pimple waiting to be popped. It is very common and as many as seventy percent of newborns are affected at some point. It is often present right at birth but can also appear during the second or third day of life. A typical lesions starts as a red bump that turns into a pustule. The pustules are usually surrounded by a little bit of redness, given a so-called “flea-bitten” appearance. The face, trunk, and limbs are most commonly involved. The cause of erythema toxicum neonatorum is not known. Individual spots generally fade over a week, but can re-occur for several weeks to months. No treatment is needed and it is totally harmless. Importantly, several infections including herpes, Candida (the fungus that causes yeast infections), and Staph infections can appear as a pustular rash in infancy; babies who appear sick, have a fever, or who’s rash doesn’t clear up in a few days should be evaluated by a pediatric dermatologist!
Transient Neonatal Pustular Melanosis
Transient neonatal pustular melanosis (another long name!) is a rash that has both vesicles (little fluid-filled bumps) and pustules. Interestingly, it occurs in up to 5 percent of black newborns, but less than 1 percent of white ones. Unlike erythema toxicum neonatorum, the lesions of transient neonatal pustular melanosis do not have surrounding redness. Additionally, these lesions are very fragile and burst easily leaving a collar of scale and pigmented spots that fades over several weeks. All areas of the body may be affected. This includes the palms and soles, which you don’t see in erythema toxicum neonatorum.
Neonatal acne occurs in about one in five newborns. It most often appears as whiteheads on the forehead, nose, and cheeks. Blackheads, red bumps, and pustules can also occur, just like in mommy! Neonatal acne is thought to result from stimulation of the oil producing glands by mom’s hormones, mostly testosterone. Individual lesions resolve within four months without scarring. No treatment is necessary but infants with more extensive or long-lasting disease can be treated with over-the-counter 2.5% benzoyl peroxide lotion. Very importantly, parents should apply a small amount of the lotion to their baby’s arm to test for allergic reactions before more widespread use or use on the face. Finally, very severe neonatal acne that doesn’t resolve within 6 months accompanied by excess hair and ambiguous genitals should raise concern for an underlying hormonal disease which should be worked up by a specialist.
Milia are tiny pearly white bumps caused by a buildup of keratin (the main protein in skin). It is extremely common, occuring in half of all newborns! It most often is found on the forehead, cheeks, nose, and chin, but the rest of the body including the genitals can be affected. Milia will disappear by itself within the first month of life, but sometimes lasts up to 3 months. It is totally harmless and no treatment is needed.
Miliaria results from a build up of sweat due to sweat gland blockage. It is also extremely common, with up to 40 percent of babies affected, usually during the first month of life. There are two main types: miliaria crystallina and miliaria rubra. In miliaria crystallina, individual spots consist of tiny fluid-filled bumps without any surrounding redness, most commonly on the head, neck, and trunk. The lesions burst leaving behind scale which may last for several days. In miliaria rubra (AKA heat rash) the lesions are small red bumps, usually occurring on covered portions of the skin. Both forms are totally harmless. Avoiding overheating, removing excess clothing, bathing with cool water, and air conditioning, especially during the summer months, can help prevent them.
Hopefully, the above list puts your mind at ease about the most common rashes you may see in your baby. Remember, if you are concerned and your baby seems sick, please seek medical care. You know your baby best! Please leave any comments below and share this article with other parents who may be interested!