Coexistent Relapsing Polychondritis and Clinically Amyopathic Dermatomyositis: A Rare Association of Autoimmune Disorders

Abstract

Relapsing polychondritis (RPC) is an uncommon autoimmune systemic disease characterized by recurrent inflammation of the cartilage tissue. It can occur alone or in association with other autoimmune diseases, vasculitis, or hematologic disorders. However, the association of RPC with dermatomyositis is extremely rare. Herein, we present a case of a 38-year-old man who developed concurrent RPC and clinically amyopathic dermatomyositis (CADM) manifested by auricular chondritis, nasal chondritis, polyarthritis, gottron papules, fingertip papules, skin biopsy consistent with dermatomyositis, and positive antimelanoma differentiation-associated gene 5 (MDA5) antibodies. RPC features resolved with corticosteroids, but CADM manifestations were resistant to corticosteroids, cyclophosphamide, azathioprine, and hydroxychloroquine. Subsequent therapy with rituximab was effective to control CADM manifestations. This case highlights the importance of recognizing CADM as part of the autoimmune diseases linked with RPC and maintaining a high level of awareness to initiate effective therapy to avoid the long-term complications associated with these conditions.

Figure 1

(a) Right and (b) left auricular involvement characterized by purplish redness and swelling of the pinna but sparing the lobules.

Figure 2

Erythematous, flat-topped, hyperkeratotic papules on the dorsal metacarpophalangeal joints bilaterally (gottron papules).

Figure 3

Biopsy of the posterior aspect of the right elbow showing perivascular lymphohistiocytic infiltration without lichenoid changes (hematoxylin and eosin stain, 100x).

Figure 4

Erythematous fingertip papules.

Figure 5

Resolution of (a) fingertip papules and (b) gottron papules after rituximab therapy.