Pruritic urticarial papules and plaques of pregnancy with unusual and extensive palmoplantar involvement

Pruritic urticarial papules and plaques of pregnancy (PUPPP) is a specific dermatosis of pregnancy common to primigravid women in the third trimester. The rash usually begins on the lower abdomen within striae and spreads to the proximal extremities. Involvement of face, palms, and soles is unusual. Although intensely pruritic, the fetus is unaffected, and the condition does not usually recur. It can be difficult to distinguish PUPPP from pemphigoid gestationis, an autoimmune bullous disorder with potential fetal consequences that may recur with subsequent pregnancy, menses, or hormonal therapy. A young secundagravida at 36 weeks of gestation with monochorionic twins presented with a 3-week history of a pruritic papular eruption that began on the abdomen and spread to the extremities. She had extensive involvement of the distal extremities, including the palmoplantar surfaces, with small vesicles of 2-4 mm on acral skin. Because of her unusual presentation, she was thought initially to have pemphigoid gestationis. Subsequent dermatological evaluation and a biopsy confirmed the diagnosis of PUPPP. Shortly after admission she delivered 2 healthy male infants, and her rash cleared with conservative management. Pruritic urticarial papules and plaques of pregnancy often, but not always, spares the face, palms, and soles. Small vesicles can occur in PUPPP, but formation of true bullae is not observed. Careful dermatological examination and cutaneous biopsy can assist in differentiating PUPPP from pemphigoid gestationis, which is essential for treatment and prognosis.