One of the most common rashes associated with pregnancy is PUPPP, or pruritic urticarial papules and plaques of pregnancy. PUPPP may also be referred to as polymorphic eruption of pregnancy. It is a "benign dermatosis," meaning it is a condition of the skin that is not considered serious. It often starts in the stretch marks of the abdomen, and typically spreads to the palms, arms, legs and feet. PUPPP, which often starts during the third trimester of pregnancy, is characterized by red bumps that look like hives, and can be extremely itchy. While a third trimester onset of PUPPP is most typical, it can also start right after delivery.

Doctors don't know exactly what causes PUPPP, but it is believed to be an inflammatory reaction to the damage of the connective tissue that occurs with stretching skin, typically on the abdomen. This is also coupled with the increase of hormones in a pregnant woman's body, specifically, estrogen. PUPPP most typically occurs with women carrying their first baby, and with twin pregnancies. One interesting recent discovery may have found a link to male fetuses — 70% of PUPPP sufferers went on to deliver boys. This link is theorized because researches identified male fetal DNA in the PUPPP rash.

Fortunately, PUPPP goes away soon after delivery, and there is a lower chance of developing it in following pregnancies. Since it can be so intensely itchy, some women may be induced a bit early if their baby is ready. During pregnancy, PUPPP may be treated with topical creams such as clobetasol and betamethasone, and antihistamines such as Benadryl®. For more serious cases, a woman may need oral steroids to help control the rash.

A woman may develop a more serious condition, called prurigo of pregnancy, which is rarer than PUPPP. It is characterized by very small bumps, sometimes all over the body, but most typically on the legs, arms, hands and feet. Rashes such as prurigo of pregnancy and PUPPP may signal another serious condition called cholestasis of pregnancy. This is a liver condition that occurs in approximately 1% of pregnant women. The flow of bile in the liver is affected, causing bile salts to build up in the skin, resulting in serious itching.

Although PUPPP is a harmless condition, it is good to consult your OB if you are experiencing any rash during pregnancy. He or she can offer you treatment to relieve your symptoms, and can rule out any more serious conditions.