Is impetigo herpetiformis a distinct clinical disease?

Impetigo herpetiformis is a rare disorder that typically presents in the third trimester. This disease is characterized by sterile pustules on an erythematous plaque initially presenting on the flexural and intertriginous areas, and then progressing to involve the trunk and remaining surfaces of the extremities. Impetigo herpetiformis can involve the mucous membranes. There also can be nail involvement, as well as systemic symptoms such as fever and malaise. It is associated with an increased risk of intrauterine growth restriction and stillbirth. Clinically and histologically, impetigo herpetiformis resembles pustular psoriasis, and it is debated whether or not impetigo herpetiformis is a distinct disease.

Lim KS, Tang MB, Nq PP: Impetigo herpetiformis—a rare dermatosis of pregnancy associated with prenatal complications, Ann Acad Med Singapore 34(9):565-568, 2005.