The annual incidence for relapsing polychondritis is about 3.5 cases per million. RP affects men and women equally and symptoms typically manifest most often in people between the ages of 40 and 60.

The exact cause of RP is unknown. It is believed to be an autoimmune disease in which the immune system attacks healthy tissue. In the case of RP, the body is attacking the healthy cartilage. RP can be triggered by an individual's genetic makeup, environment, and/or family medical history.

Some believe that RP can be due to a sensitivity to Type II Collagen, which is a naturally occurring substance found in connective tissue. Some believe RP is not an inherited disease, but affected individuals are more than likely to carry a gene called HLA-DR4. HLA-DR4 does not cause RP, but this gene, along with other unknown genetic factors, triggers, and environment can contribute to the presence of RP.

The onset of RP begins with the sudden pain and swelling of the cartilage. The attacks can last for several days to weeks. It can lead to the deterioration of the cartilage. Other symptoms such as, fever, weight loss, or fatigue may also be present.  Symptoms of RP vary for each affected individual depending on the location of the inflamed cartilage.

The ears are the most commonly affected by RP. The outer part of the ear loses its firmness and becomes “floppy”. The inner ear can become inflamed and hearing can be impaired. Some affected individuals will develop “floppy” ears at the onset of RP. Almost all affected individuals will develop “floppy” ears at some point.

The joints are the second most commonly affected area by RP. The symptoms feel similar to arthritis. Similarly to the ears, some affected individuals will feel joint pain at the onset of RP. Almost all affected individuals will feel joint pain at some point.

The nose cartilage can be inflamed, leading to congestion, nosebleeds, crusting, excessive mucus, nose deformity, and potentially the loss of smell. A small handful of affected individuals will develop this symptom at onset and about half will develop it at some point.

The airways: the trachea, larynx, and bronchi are airway structures that are made up of cartilage. An inflamed airway causes coughing, wheezing, recurrent pulmonary infection, and difficulty breathing. A handful of affected individuals will develop this symptom at onset and about half will develop it at some point.

The eyes can be inflamed, leading to redness, bulging eyes, and possibly loss of vision. This symptom is very rare at onset and about half will develop it at some point.

Other organs that can be affected by RP are the heart, the kidneys, the nervous system, the rib cage, and the gastrointestinal tract.

The diagnosis of RP can be difficult since symptoms are similar to other diseases.  The initial ear and nose symptoms are thought to be an infection requiring antibiotics. Sometimes the symptoms improve on their own, so it may be thought that antibiotics may be affecting an ear or nose infection. The frequency of flare ups and pain can be variable so it may take many episodes of symptoms before the individual can be properly diagnosed.

The diagnosis of RP is dependent on the presence of symptoms: inflammation of cartilage on both ears, arthritis of the joints, inflamed cartilage of the nose, inflammation in the eye, inflammation in the throat, and/or vestibular dysfunction.

There is no test available to specifically identify RP. Diagnosis is dependent on the practitioner’s examination of symptoms.

A biopsy of the affected cartilage can be used to confirm diagnosis.

The treatment for RP is focused on treating the debilitating symptoms of RP and preserving the physical structure of the affected cartilage. Mild symptoms can be treated with anti-inflammatory drugs, non-steroid anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, or dapsone. Moderate symptoms include treatment with NSAIDs and corticosteroids, such as prednisone. Severe cases may require immunosuppressant medications, such as cyclosporine or azathioprine, or biologic injections, such as infliximab or etanercept. Life threatening cases may require heart valve replacements or insertion of breathing tubes. Surgery may be necessary to correct collapsed or narrowing of the trachea.

The prognosis for affected individual varies by symptom severity and disease progression. RP is degenerative and chronic. The longer the affected individual has RP, the worse RP becomes. There are a handful of disabilities associated with RP, such as hearing and visual impairment. RP becomes life-threatening with the respiratory tract collapse or the heart becomes damaged.

The prognosis has improved for RP recently due to improved healthcare.

1.       https://rarediseases.org/rare-diseases/relapsing-polychondritis/

2.       https://rarediseases.info.nih.gov/diseases/7417/relapsing-polychondritis

3.       https://www.brighamandwomens.org/medicine/rheumatology-immunology-allergy/services/relapsing-polychondritis

4.       https://www.merckmanuals.com/home/bone,-joint,-and-muscle-disorders/autoimmune-disorders-of-connective-tissue/relapsing-polychondritis