Impetigo Herpetiformis is a rare condition that has been reported in less than 100 pregnant women. The disease is similar to a type of psoriasis called pustular psoriasis, although women with impetigo herpetiformis usually have no personal or family history of psoriasis. Doctors disagree about whether impetigo herpetiformis is a distinct disease caused by pregnancy or a form of pustular psoriasis triggered by pregnancy.
Impetigo herpetiformis typically begins in the last trimester of pregnancy. The rash usually resolves after delivery but can recur in subsequent pregnancies. The rash begins as pus-filled bumps, or pustules, on the edges of a red area of skin on the inner thighs and groin. The pustules join and spread to the trunk and extremities, usually sparing the face, hands, and feet. However, the rash can spread to the mucous membranes in the mouth and the nail beds. Even though pus is present, these lesions are not infected with bacteria, although they can become infected in the course of the disease.
Impetigo herpetiformis is frequently accompanied by significant symptoms such as fever, chills, nausea, vomiting, diarrhea, and fatigue. Some women experience low levels of calcium and phosphate in the blood. Women who have a parathyroid disorder called hypoparathyroidism may be susceptible to this condition during pregnancy as calcium and albumin levels in the blood fall.
Impetigo herpetiformis is usually diagnosed clinically by observing the symptoms and characteristic rash. A skin biopsy is typically performed to rule out other pregnancy-related conditions.
Impetigo herpetiformis is treated with the oral steroid, prednisone. The beginning dose is usually fairly high and then tapered very slowly once symptoms are under control. Antibiotics are only used if the rash becomes secondarily infected. Blood levels of calcium, phosphate, and albumin are monitored throughout the course of the disease.
Effect on Baby
Impetigo herpetiformis does appear to put the infant at higher risk of stillbirth and placental insufficiency. Women with this condition should be closely monitored by a team of physicians to include dermatologists, obstetricians, and pediatricians.