Background Relapsing polychondritis (RP) is so rare that controlled therapy trials have not been carried out. Therefore, strategies for the treatment of RP refractory to moderate- or high-dose corticosteroids (CS) have not been established.

Objectives To report a severe case of RP, refractory to CS, in which complete remission was induced by cyclophosphamide (CP) therapy.

Methods Retrospective clinical and laboratory analysis of one patient.

Results A 55-year-old Caucasian woman developed ear and nose cartilage inflammation, for the first time, when she was 31. At that time a biopsy of auricular cartilage confirmed the clinical diagnosis of RP. The disease responded to an initial short-term CS therapy (20 mg prednisolone/day), but a maintenance dose of 5–10 mg prednisolone/day was required to control symptoms and prevent relapses ever since. Meanwhile, she developed diabetes mellitus and cataract. Additionally, she had chronic anaemia due to thalassemia minor. Sixteen months ago, after strenuous physical exercise, a severe relapse of the disease occurred suddenly. The patient presented with acute arthritis of the knees and wrists, chondritis of the auricular, nasal, and laryngotracheal cartilages, as well as symptoms of eye inflammation. She complained of severe arthralgias, hoarseness, cough, eye irritation, tinitus, and vertigo. Physical examination revealed fever (38°C), tenderness of thyroid cartilage and the anterior trachea, bilateral episcleritis and cataract, cochlear and vestibular dysfunction, and effusion of both knees. Laboratory investigation showed an erythrocyte sedimentation rate of 41 mm, C-reactive protein 15.5 mg/dl (normal <0.9 mg/dl), glucose 216 mg/dl, hematocrit 35%, haemoglobin concentration 10.3 g/dl, white blood cell count 10,540/μl with 71% polymorphs, platelet count 477,000/μl, negative rheumatoid factor, microscopic hematuria, and inflammatory synovial fluid, containing 15,800 white cells/μl (95% polymorphs, 5% lymphocytes), but no crystals or microorganisms. The manifestations of laryngotracheal, ocular, and inner ear inflammation were refractory to 60 mg prednisolone/day for four weeks. Then, oral CP (1.5 mg/Kg/day) was added and a quick improvement ensued. Within four months of CP therapy complete clinical remission of the disease and normalisation of laboratory tests was observed. Subsequently, CP was discontinued and prednisolone was gradually tapered off over the next six months. Eventually, five months after stopping CS, the disease still remains quiescent without therapy.

Conclusion Although RP may have a remitting course, the remission in our patient has most likely been induced by CP in combination with prednisolone. Our observation suggests that CP is an effective therapy for severe cases of RP refractory to CS alone. Moreover, CP seems capable of inducing sustained remission of this disease.