An uncommon presentation of an uncommon disease: relapsing polychondritis overlap with systemic lupus erythematosus.

Relapsing polychondritis (RP) is a rare rheumatologic disorder in which recurrent episodes of inflammation result in destruction of cartilage of the ears and nose. The joints, eyes, audio-vestibular system, heart valves, respiratory tract, kidneys, and skin can also be involved. Skin involvement is most frequently linked to concomitant myelodysplastic syndrome and has rarely been associated with systemic lupus erythematosus. A 47-year-old woman presented with violaceous, indurated, tender plaques on the bilateral cartilaginous ears with sparing of the lobes, consistent with RP. Further investigations revealed positive ANA and anti-Smith antibody, oral ulcers, a photo-distributed skin eruption, and biopsy-proven lupus nephritis, leading to a second concomitant diagnosis of systemic lupus erythematosus (SLE). The diagnosis of SLE associated with RP was made and the patient was started on oral prednisone and hydroxychloroquine. This is a rare report of SLE associated with RP. It is unclear whether RP occurring in patients with SLE represents another clinical manifestation of SLE or a coexisting disease. However, a significant ANA titer in a patient with RP strongly suggests the presence of an associated autoimmune disorder. If immunologic abnormalities usually found in SLE are detected in patients with RP, it is important to monitor patients for the development of other manifestations of SLE.