LAUSR

Dear Editor, We read with interest the article by Baffa et al., who reported a case of severe bullous pemphigoid (BP) developed 10 days after the second dose of Pfizer/BioNtech BNT162b2 mRNA vaccine against Covid19, resistant to rituximab and successfully treated with dupilumab. We report herein a case of severe BP developed 3 days after the second dose of the same vaccine in a 79yearold woman, refractory to oral prednisolone and successfully treated with intravenous immunoglobulin (IVIG). The patient was referred to the Burn Unit of our hospital due to a 1month history of pruritic bullous dermatosis. Her medical history was notable for primary hypertension and obesity (IMC 38.1 kg/m). Physical examination showed erythematous and hemorrhagic erosions involving her trunk and limbs, affecting around 20% of the body surface area (Figure 1). A few blisters filled with serous exudate were also noted. The mucosal surfaces were not involved and the Nikolsky sign was negative. She denied recent medication introduction other than COVID19 vaccination. She also reported generalized erythema and pruritus after the first dose of the same vaccine. Given the suspicion of BP, oral prednisolone 0.7 mg/kg/day was initiated 2 weeks before the referral to the Burn Unit. We performed a lesional and perilesional skin biopsy on the abdomen, for histopathological examination and direct immunofluorescence (DIF), respectively. The skin biopsy was consistent with BP (Figure 2) and the DIF showed linear deposition of IgG and C3 along the basement membrane zone. ELISA demonstrated elevated IgG autoantibodies antiBP180 (151 UI/mL, N < 20) and antiBP230 (230 UI/mL, N < 20). Based on these findings, the diagnosis of BP was made. A chest, abdomen and pelvis CT scan was performed and did not reveal any occult malignancy. Due to the clinical worsening regardless of oral prednisolone, topical betamethasone, 100 mg/day of doxycycline, and 100 mg twice/day of mycophenolate of mofetil, IVIG 2 g/kg was administrated for 5 consecutive days. After 2 weeks, the erosions healed and the patient did not develop new blisters, leading to the progressive tapering of oral prednisolone. Received: 1 December 2022 | Accepted: 5 January 2023