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Multiple facial ulcers as a presentation of localized granulomatosis with polyangiitis associated with IgG4‐related disease

An overlap disease between IgG4-related disease (IgG4-RD) and antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) was proposed in 2017. IgG4-RD with localized AAV has rarely been reported. A 48-year-old man presented with an 8-month history of multiple ulcers on his face and scalp (Fig. 1a–c). When he had presented previously to a different hospital, PCR for Mycobacterium tuberculosis complex and a pus culture were negative. A skin biopsy taken at the time showed a necrotizing granulomatous inflammation without vasculitis. Following this, the patient had received several courses of oral antibiotics without any improvement. We performed computed tomography scans of the orbit and paranasal sinuses, which showed right orbital cellulitis with dacryocystitis and dacryoadenitis and right ethmoidal sinusitis. Histological examination of a skin biopsy from the patient’s eyelid and cheek revealed dense infiltration by lymphocytes and plasma cells, with arteritis (Fig. 1d–g). Immunostaining showed IgG4+ plasma cells at 200–250 cells/high power field (HPF), with an IgG4+/IgG+ ratio of 30% (Fig. 1h,i). Laboratory investigations showed mild anaemia without hypereosinophilia and an IgG4 level of 573 mg/dL (11–330 mg/dL). Tests for ANCAs and serology testing for HIV were negative. Given the clinical presentations and the histopathological evidence of arteritis, IgG4-RD associated with localized granulomatosis with polyangiitis (GPA) was suspected. IgG4-RD is characterized by elevated serum IgG4 levels and abundant infiltration of IgG4+ plasma cells into the affected organ. The diagnostic criteria are: (i) diffuse or localized swellings or masses, with single or multiple organ involvement; (ii) elevated serum IgG4 levels of ≥ 135 mg/dL; and (iii) histopathology revealing (a) marked lymphocyte and plasma cell infiltration, and (b) fibrosis and infiltration of IgG4+ plasma cells, with an IgG4+/IgG+ ratio ≥ 40% and ≥ 10 IgG4 + plasma cells/HPF. All three criteria are needed to make a definite diagnosis. Classic histopathological features are required for probable diagnosis whereas possible IgG4-RD includes organ involvement and elevated IgG4 levels. The diagnosis in our patient was possible as he had eye and skin involvement, elevated serum IgG4 levels and almost all the histopathology findings of IgG4-RD, except an IgG4+/IgG+ ratio ≥ 40%. Localized GPA, a rare distinctive subset of AAV, can present with mucocutaneous lesions without systemic organ involvement. The cutaneous lesions are usually located on the face with variable morphologies, such as plaques, nodules and ulcers. The nasal and palatal mucosae are almost always affected. ANCA can be absent in up to 40% of patients with localized GPA. Danlos et al. reported on a large case series of 18 patients with IgG4-RD/AAV. Among AAV, GPA was found to be the most common AAV that overlapped with IgG4-RD (14/18), followed by microscopic polyangiitis (3/18) and eosinophilic granulomatosis with polyangiitis (1/18). Of the 14 patients with GPA, 2 had limited GPA, but no facial ulcers were reported for any of the 18 patients. Therefore, our case is quite unique as the patient Correspondence: Dr Leena Chularojanamontri, Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, 2 Wanglang Road, Bangkok Noi, Bangkok 10700, Thailand E-mail: leenajim@gmail.com