Relapsing polychondritis or relapsing polychondritis-like symptoms associated with IgG4-RD. Case reports and review of the literature.

Relapsing polychondritis (RP) is a rare systemic disorder characterised by recurrent, widespread chondritis of the auricular, nasal, and tracheal cartilages. Immunoglobulin G4-related disease (IgG4-RD) is a systemic immune-mediated disease characterised by the infiltration of IgG4-bearing plasma cells into systemic organs. However, 25-35% of patients with RP have a concurrent autoimmune disease. The coexistence of RP and IgG4 is rare considering that, to the best of our knowledge, there are only four previous reports of RP or RP-like symptoms associated with IgG4-RD. We herein report two cases which could be RP or RP-like symptoms associated with IgG4-RD.