A Case of Relapsing Polychondritis: Unmasking the Otitis Externa Mimic.

Relapsing polychondritis (RPC) is a rare autoimmune condition that often mimics recurrent external otitis. This multisystemic disease primarily affects cartilaginous structures in the body, with the ear pinna being the most commonly impacted. RPC is associated with elevated inflammatory markers and antinuclear antibodies (ANA), and it can lead to chondral destruction. Our case is a 74-year-old Caucasian male with a history of peripheral vascular disease (PVD) who presented to the clinic with recurrent, painful swelling of the right upper ear for 14 days despite multiple antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs). He had chronic sensorineural hearing loss in the same ear. He was seen multiple times with identical symptoms in the last seven months and was diagnosed with otitis externa. He denied arthritis, fatigue, rash, abrasion, allergies, trauma, or fever. He was prescribed antimicrobials, alternating NSAIDs, and methylprednisolone with temporary relief. He is only on statins and has an unremarkable family history. He was afebrile with normal vital signs. On physical examination, he was not in acute distress and had a normal voice but had a diffusely erythematous, tender, swollen right ear pinna and external canal sparing the lobe. The rest of the physical examination was unremarkable. Laboratory results showed elevated C-reactive protein (CRP) of 100 mg/L (normal range: <3 mg/L) and erythrocyte sedimentation rate (ESR) of 200 mm/hour (normal range: <20 mm/hour). ANA titer is 1:160 with a homogenous pattern, but other autoantibodies were negative. No red flags were noted on the complete blood count (CBC) or comprehensive metabolic panel (CMP), and his rapid plasma reagin (RPR) test was negative. In this patient, prednisone 60 mg daily was initiated as monotherapy, and rheumatology was also consulted. The patient sought consultation due to recurrent and persistent upper ear infections despite antibiotic treatment and was ultimately diagnosed with a rare medical condition called relapsing polychondritis. Following this treatment, the auricular chondritis improved promptly. The steroid dosage was then slowly tapered and maintained at 10 mg daily to prevent flare-ups. Subsequently, after the initiation of corticosteroids, inflammatory markers trended down to normal levels.