Pemphigoid gestationis in a primigravida: autoimmune dermatosis of pregnancy — a rare case report

Abstract

Pemphigoid gestationis (previously termed pemphigus gestationis) is a rare autoimmune vesiculobullous dermatosis unique to pregnancy, with an estimated incidence of approximately 1 in 50,000 pregnancies. It is mediated by maternal IgG autoantibodies directed against BP180 (collagen XVII), resulting in complement activation and subepidermal blister formation. The disease typically presents during the second or third trimester with severe pruritus followed by erythematous urticarial plaques and tense bullous lesions. We report the case of a 22-year-old primigravida at 34 weeks and 3 days of gestation who presented with generalized pruritus and multiple vesiculobullous skin lesions involving the abdomen, trunk, upper limbs, thighs, and face. Histopathology and direct immunofluorescence confirmed the diagnosis of pemphigoid gestationis. The condition was complicated by fetal growth restriction and abnormal Doppler findings, necessitating preterm emergency caesarean delivery. The patient was managed with systemic corticosteroids and multidisciplinary care, resulting in favorable maternal and neonatal outcomes. Although uncommon in primigravida women, pemphigoid gestationis should be considered in the differential diagnosis of pregnancy-associated pruritic dermatoses. Early diagnosis using histopathology and direct immunofluorescence, along with prompt treatment and close fetal surveillance, is essential to improve fetomaternal outcomes.