There are a number of different rashes that can develop on a woman's body during pregnancy. The hormonal changes that the body goes through are often to blame for these conditions. The rashes can range from ones that are itchy and annoying, but not serious, to conditions that are potentially life-threatening to the baby. There is often no cure for these rashes. They resolve once the baby is delivered, and the body gets back to normal.
PUPPP
PUPPP stands for Pruritic Urticarial Papules and Plaques of Pregnancy. This is an 
extremely itchy rash that first develops on the abdomen and spreads from there. It becomes a red, raised rash that can cover the abdomen, buttocks, and thighs and can spread to the arms and legs. It normally doesn't appear on the patient's face. PUPPP doesn't pose any risk to the baby. Antihistamines and corticosteroid creams are the most common treatments. PUPPP is the most common pregnancy rash
.
Prurigo of Pregnancy
Prurigo of pregnancy doesn't pose any risk to the baby, but it can continue for several weeks or even months after delivery. It shows up as itchy pink or red bumps on the arms and legs and sometimes other body parts. Corticosteroid creams and antihistamines help control the itching.
Intrahepatic Cholestasis of Pregnancy
This presents itself as a severe rash during the third trimester. It's caused by elevated levels of bile fluids in the mother's system when the liver slows down due to pregnancy hormones. It carries a risk of premature birth and even death of the baby if it's not caught early enough. Medicines that reduce the amount of bile in the mother's system will be prescribed, along with anti-itch creams for the rash itself. This is a serious condition for the baby and can affect his liver. Other treatment options and medications may focus on preserving the baby's health. Intrahepatic cholestasis of pregnancy goes away after delivery.
Pemphigoid Gestationis
Pemphigoid gestationis is much more uncommon than the previous rashes, affecting only one out of every 50,000 pregnancies in the U.S. It's an autoimmune condition that shows up as round patches on the abdomen initially. It usually spreads from there, but typically doesn't affect the mother's face, scalp, or neck. Severe cases of this rash require oral corticosteroids to help manage the symptoms. It carries a risk of premature delivery and low birth weight for the baby, and sometimes the baby will have lesions from the condition when he is born.
Impetigo Herpetiformis
This is a rare condition that shows up in the second half of pregnancy. The lesions from the rash can break open and release pus, and then the open sores can lead to secondary infections after impetigo. There are increased instances of infant mortality associated with this rash. Aggressive treatment with systemic corticosteroids and antibiotics is required. Impetigo herpetiformis goes away after delivery.
Pruritic Folliculitis of Pregnancy
This one presents as a rash on the abdomen, back, arms, and legs. It poses no risk to the baby, and it resolves soon after the baby is born. Corticosteroid creams can help relieve the itching, and doctors have had success in treating it with ultraviolet light therapy as well.