Maternal and neonatal pemphigoid gestationis

Pemphigoid gestationis (PG) is an uncommon autoimmune bullous disease that appears during pregnancy or in association with trophoblastic tumours. While it almost invariably recurs in subsequent pregnancies,1 the risks to the foetus or neonate in PG have historically been controversial.2 We describe a patient whose first pregnancy was complicated by PG and who had a severe postpartum flare; her infant developed a rash in the neonatal period. A 24‐year‐old woman presented during the 32nd week of her first pregnancy with a 3‐week history of a pruritic rash involving the legs and arms which later spread to involve the trunk. Her pregnancy was otherwise uncomplicated. Physical examination revealed widespread eruption of tense blisters arising on urticated erythema on almost the whole body surface with more severe involvement of the extremities. Target lesions, interspersed among the bullous and erythematous lesions, were also notable (Fig. 1). The mucous membranes were spared. The patient was otherwise in good general health. There was no personal or family history of any autoimmune disorder, blistering or otherwise. Histological examination of an intact blister showed a subepidermal blister; the margin showed epidermal acanthosis and spongiosis with exocytosis of eosinophils. The dermis showed oedema, with a perivascular mixed inflammatory cell infiltrate of lymphocytes, histiocytes and abundant eosinophils. Direct immunofluorescence (IF) showed C3 and C4 deposition along the basement membrane zone (BMZ). A serum sample was examined by indirect IF using normal human skin split by 1 mol/L NaCl as substrate and was strongly positive for staining at the epidermal side of the BMZ. The patient's haematological profile, urinalysis, liver function tests, renal function tests and blood sugar estimations were normal. The clinical findings along with the histological features and the IF studies confirmed the diagnosis of PG.