Clinical Images: Multiple blisters on the upper and lower extremities in granulomatosis with polyangiitis

The patient, a 51-year-old woman, was admitted for an evaluation of productive cough and progressive rash on the extremities for three months. Physical examination revealed right scleral and conjunctival injection, right conductive hearing loss, sinus tenderness with epistaxis, coarse crackles in the lungs, and multiple fingertip-sized blisters on the extremities that ulcerated after puncture (A). Laboratory findings showed an eosinophil count of 550 per μL, CRP 10.0 mg/dL, creatinine 0.3 mg/dL, MPO-ANCA <1.0 U/mL, and PR3-ANCA 180 U/mL. Magnetic resonance imaging revealed fluid accumulation with T2 hyperintensity in the right mastoid air cells and maxillary sinus, with wall thickening in the latter (B). Computed tomography revealed multiple lung cavitary lesions (C). Pemphigus and pemphigoid were considered differential diagnoses. Skin biopsy showed neutrophil-dominant inflammatory cell infiltration around blood vessels from the superficial to deep dermis. Some vascular structures were disrupted, with extravasation of red blood cells and nuclear debris, suggesting vasculitis (D and E). The patient was diagnosed with granulomatosis with polyangiitis (GPA) and treated with methylprednisolone pulse therapy, followed by prednisolone (1 mg/kg), rituximab, and avacopan. Prednisolone was tapered according to the rapid tapering protocol of the Plasma Exchange and Glucocorticoids in Severe Antineutrophil Cytoplasmic Antibody-Associated Vasculitis trial,1 considering the risk of delayed wound healing and skin ulcer-associated infection. All skin lesions epithelialized within approximately one month, and GPA remission was achieved within three months. Although vasculitis-associated blisters have been reported in eosinophilic granulomatosis with polyangiitis and IgA vasculitis, they are rare in patients with GPA.2 Vascular injury, primarily in the superficial dermis with increased permeability, may cause blisters instead of purpura or ulcers, whereas severe organ damage suggests deeper vascular involvement.3 Early glucocorticoid tapering or sparing therapy with rituximab or avacopan may be effective in treating GPA-associated blisters. Disclosure form. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.