Auricular inflammation is a hallmark of RP and is present in 83% to 95% of patients.1,3 The affected ears can appear erythematous to violaceous with tender edema of the auricle that spares the lobules where no cartilage is present. The inflammation can extend into the ear canal and cause hearing loss, tinnitus, and vertigo. Histologically, RP can present with a nonspecific leukocytoclastic vasculitis and inflammatory destruction of the cartilage. Therefore, diagnosis of RP is reliant mainly on clinical characteristics rather than pathologic findings. In 1976, McAdam et al5 established diagnostic criteria for RP based on the presence of common clinical manifestations (eg, auricular chondritis, seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation). Michet et al6 later proposed major and minor criteria to classify and diagnose RP based on clinical manifestations. Diagnosis of our patient was confirmed by the presence of auricular chondritis, polyarthritis, and ocular inflammation. Diagnosing RP can be difficult because it has many systemic manifestations that can evoke a broad differential diagnosis. The time to diagnosis in our patient was 3 months, but the mean delay in diagnosis for patients with RP and ME is 2.9 years.4
The etiology of RP remains unclear, but current evidence supports an immune-mediated process directed toward proteins found in cartilage. Animal studies have suggested that RP may be driven by antibodies to matrillin 1 and type II collagen. There also may be a familial association with HLA-DR4 and genetic predisposition to autoimmune diseases in individuals affected by RP.1,3 The pathogenesis of CNS involvement in RP is thought to be due to a localized small vessel vasculitis.7,8 In our patient, however, cerebral angiography was negative for vasculitis, and thus our case may represent another mechanism for CNS involvement. There have been cases of encephalitis in RP caused by pathways other than CNS vasculitis. Kashihara et al9 reported a case of RP with encephalitis associated with antiglutamate receptor antibodies found in the cerebrospinal fluid and blood.
Treatment of RP has been based on pathophysiological considerations rather than empiric data due to its rarity. Relapsing polychondritis has been responsive to steroid treatment in reported cases as well as in our patient; however, in cases in which RP did not respond to steroids, infliximab may be effective for RP with ME.10 Further research regarding the treatment outcomes of RP with ME may be warranted.
Although rare, additional cases of RP with ME have been reported (Table). Wang et al4 described a series of 28 patients with RP and ME from 1960 to 2010. A PubMed search of articles indexed for MEDLINE that were published in the English-language literature from 2010 to 2016 was performed using the search terms relapsing polychondritis and nervous system. Including our patient, RP with ME was reported in 17 additional cases since Wang et al4 published their findings. These cases involved adults ranging in age from 44 to 73 years who were mainly men (14/17 [82%]). All of the patients presented with bilateral auricular chondritis, except for a case of unilateral ear involvement reported by Storey et al.11 Common neurologic manifestations included fever, headache, and altered mental status. Motor symptoms ranged from dysarthria and agraphia12 to hemiparesis.13 The mechanism of CNS involvement in RP was not identified in most cases; however, Mattiassich et al14 documented cerebral vasculitis in their patient, and Niwa et al16 found diffuse cerebral vasculitis on autopsy. Eleven of 17 (65%) cases responded to steroid treatment. Of the 6 cases in which RP did not respond to steroids, 2 patients died despite high-dose steroid treatment,11,20 2 responded to infliximab,10,15 1 responded to tocilizumab,21 and 1 was lost to follow-up after initial treatment failure.20