Relapsing Polychondritis

Original Editor - Pacifique Dusabeyezu
Top Contributors - Pacifique Dusabeyezu, Kim Jackson and Carina Therese Magtibay

Introduction

Relapsing polychondritis (RP) is a rare multisystem autoimmune condition with an unknown cause. It is characterized by recurring episodes of inflammation that lead to the gradual destruction of various cartilaginous tissues in the body. This includes elastic cartilage found in the ears and nose, hyaline cartilage in peripheral joints, fibrocartilage in the spine, and cartilage in the tracheobronchial system. RP can affect structures rich in proteoglycans, such as those in the eye, heart, blood vessels, and inner ear.

Etiology

The etiology of Relapsing polychondritis remains unknown so far, and the pathogenesis appears to be mediated by an autoimmune reaction to type II collagen, which is abundant in cartilage and the sclera.

Clinical Presentation

The clinical presentation of people with RP varies from person to person and may include different organ systems. The most common clinical features and symptoms of relapsing polychondritis are as follows:

• Auricular Chondritis: is the most common feature of RP, affecting up to 90% of patients and is a symptom of first-line diagnosis in 20% of cases. In individuals with RP, the ear's cartilage matrix is severely inflamed and replaced by fibrous connective tissue, leading to a loss of normal morphology. This often presents as painful, red, swollen ears that may be misshapen due to cartilage damage. Hearing loss, either conductive or sensorineural, is observed in 46% of patients with RP, while vestibular dysfunction is documented in 6%.
• Nasal Chondritis: This condition also affects 24% of patients, develops in 53% of cases. It causes acute redness, tenderness, and pain, often accompanied by epistaxis. The condition lead to a collapsed nose bridge, saddle-nose deformity, and nasal congestion.
• Arthropathy: is the second most common symptom in RP, appearing in 50-85% of patients. It's a pattern of joint involvement affecting metacarpophalangeal, proximal, and knee joints. Joint destruction is rare, and tendinopathy and tenosynovitis are rare.
• Ocular manifestations: in Relapse polychondritis are usually mild and include episcleritis, scleritis, and conjunctivitis. Less frequently, RP can cause other conditions like iritis, retinopathy, muscle paresis, anterior uveitis, optic neuritis, occlusion of retinal arteries, and cataract.
• Respiratory symptoms are very common in individuals with RP and can be lethal, with 25% of patients presenting symptoms at the onset and increasing to 50% during the disease. Inflammation in the larynx, trachea, and broncial cartilage, hoarseness, dry cough, shortness of breath, wheezing, and stridor are common.

Epidemiology

RPC affects 1 in 1.4 million people per year in the UK, with a standardized mortality ratio of 2.16. Onset may be sudden, although in mild cases it can be insidious. Peak incidence is in the fifth decade of life (40–55 years old), but the disease has been described in young children and the very elderly. Relapsing polychondritis (RP) primarily affects middle-aged adults, with a slight tendency towards affecting more women than men. In the United States, RP has an estimated annual incidence of 3.5 cases per one million people in the population, and among Department of Defense beneficiaries, the prevalence is approximately 4.5 cases per ten million individuals.

Diagnostic Procedures

add text here relating to diagnostic tests for the condition

Outcome Measures

add links to outcome measures here (see Outcome Measures Database)

Management / Interventions

add text here relating to management approaches to the condition

Differential Diagnosis

add text here relating to the differential diagnosis of this condition

Prognosis

Most individuals with RP typically experience a variable disease course marked by intermittent episodes of inflammation. During each flare-up, the specific sites affected and the severity of involvement tend to change and are not consistent. Many patients also deal with persistent symptoms in between these acute episodes.

Fortunately, with better management of RP-related complications, survival rates have significantly improved. For instance, in 1986, the 10-year survival rate was only 55%, but by 1998, it had risen to an impressive 94% at the end of 8 years. The primary causes of mortality in these individuals include lower respiratory tract infections, airway collapse, cardiac issues like valvular disease, and advanced systemic vasculitis.