A 38-year-old man with undifferentiated connective tissue disease (UCTD) presented with a 3-week history of pruritic, erythematous-to-brownish papules, macules, and patches on the face, trunk, extremities, and right palm ( Fig. 1 a). He had received rituximab and belimumab for 5 years, with the last dose administered 5 months earlier. Maintenance medications included hydroxychloroquine, colchicine, and celecoxib. He reported unprotected heterosexual intercourse and travel to Japan within the past 6 months. No fever, headache, lymphadenopathy, or genital lesions were observed. Belimumab was re-administered for a presumed UCTD flare without improvement. Serologic tests for syphilis, including rapid plasma reagin (RPR) and chemiluminescent microparticle immunoassay (CMIA), as well as a test for HIV antigen/antibody, were negative. Immunologic evaluation revealed B-cell depletion and hypogammaglobulinemia (IgG 830 mg/dL reference, 635-1741 mg/dL, IgM 25 mg/dL reference, 45-281 mg/dL, and CD19+ B cells <2 cells/μL), consistent with the effects of belimumab. Abbreviation: RPR, rapid plasma reagin.
Lin et al. (Sun,) studied this question.