A 58-year-old female with a 3-year history of adult-onset asthma, bilateral blepharoptosis, dry eye, and yellow-orange xanthelasma-like plaques extensively involving both upper eyelids presented with a diagnosis of adult-onset asthma with periocular xanthogranuloma (AAPOX) and systemic IgG4-related disease. Over the next 8 years, she received 10 intralesional triamcinolone injections (40–80 mg) in the right upper eyelid, 7 intralesional triamcinolone injections (30–60 mg) in the left upper eyelid, underwent right anterior orbitotomy twice followed by 4 doses of rituximab (1000 mg intravenous infusion) without regression of the AAPOX. The patient was then treated with 2 monthly doses of Truxima (1000 mg intravenous infusion), a biosimilar to rituximab. At the most recent follow-up, 13 months later, the xanthelasma-like plaques and orbital infiltration had markedly improved. To the best of the authors’ knowledge, this is the first report of Truxima being used to treat AAPOX with systemic IgG4-related disease and to generate a sustained clinical response.