Pruritic Urticarial Plaques and Tense Bullae During a Second Trimester Pregnancy

Introduction. A 34-year-old woman at 24 weeks gestation presented to the dermatology clinic with a 1-month history of worsening, painful, and pruritic skin eruption.

History. The patient’s history was remarkable for biopsy-confirmed dermatitis during the third trimester of a prior pregnancy. Direct immunofluorescence (DIF) at that time was non-contributory. Because her dermatitis had not completely resolved postpartum, she was placed on dupilumab 300 mg every other week. Because of persistent pruritus of the hands and feet, she was placed on tralokinumab 300 mg injections every other week for 3 months. She was asymptomatic prior to her current presentation. On physical examination, widespread urticarial plaques progressing to tense bullae were noted on the arms (Figs. 1-3) and legs (Fig. 4). The eruption extended over her trunk. The remainder of her physical examination was unremarkable.

Figure 1A-D. Widespread urticarial plaques with tense bullae over the patient's arms and legs are shown.

Diagnostic Testing. Two shave biopsies were performed: Left arm medial biopsy for hematoxylin and eosin staining and left arm lateral biopsy for perilesional DIF analysis. (Figures 2-3)


Figure 2. DIF reveals linear deposition of C3. IgA and IgG fail to reveal significant staining.

Figure 3. Hematoxylin and eosin–staining (original magnification ×200) revealed subepithelial blister formation with numerous eosinophils noted within the blister cavity.

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