Relapsing polychondritis is a multi-systemic condition characterized by repeated episodes of inflammation and deterioration of cartilage. The often painful disease can cause joint deformity and be life-threatening if the respiratory tract, heart valves, or blood vessels are affected. The exact mechanism is poorly understood, but it is thought to be related to an immune-mediated attack on particular proteins that are abundant in cartilage. The diagnosis is reached on the basis of the symptoms and supported by investigations such as blood tests and sometimes other investigations. Treatment may involve symptomatic treatment with painkillers or anti-inflammatory medications, and more severe cases may require suppression of the immune system. Signs and symptoms Though any cartilage in the body may be affected in persons with relapsing polychondritis, in many cases the disease affects several areas while sparing others. The disease may be variable in its signs and symptoms, resulting in a difficult diagnosis which may leads to delayed recognition for several months, years or decades. Joint symptoms are often one of the first signs of the disease with cartilage inflammation initially absent in nearly half the cases. Associated diseases There are several other overlapping diseases associated with RP, that should also be taken into account. About one-third of people with RP might be associated with other autoimmune diseases, vasculitides and hematologic disorders. Systemic vasculitis is the most common association with RP, followed by rheumatoid arthritis and systemic lupus erythematosus. The following table displays the main diseases in association with RP. Cartilage inflammation Cartilage inflammation (technically known as chondritis) that is relapsing is very characteristic of the disease and is required for the diagnosis of RP. These recurrent episodes of inflammation over the course of the disease may result in breakdown and loss of cartilage. The signs and symptoms of cartilage inflammation in various parts of the body will be described first. Ear Inflammation of the cartilage of the ear is a specific symptom of the disease and affects most people. It is present in about 20% of persons with RP at presentation and in 90% at some point. Both ears are often affected but the inflammation may alternate between either ear during a relapse. It is characteristic for the entire outer part of the ear except the earlobe to be swollen, red, or less often purplish, warm and painful to light touch. The inflammation of the ear usually lasts a few days or more,