Rheumatoid arthritis (synonyms: Arthritis; Chronic polyarthritis; Polyarthritis chronica progressiva; Polyarthritis rheumatica; Primary chronic polyarthritis (PcP); Primary chronic polyarthritis; Rheumatoid arthritis; pcP; ICD-10 M05.-: Seropositive chronic polyarthritis; M06.-: Other chronic polyarthritis) is a chronic inflammatory multisystem disease that usually manifests as synovitis (inflammation of the synovial membrane). It predominantly affects the joints (polyarthritis, i.e. arthritis of ≥ 5 joints), and more rarely other organs such as the eyes and skin. Special forms of rheumatoid arthritis:
- Age form of rheumatoid arthritis – English “late onset rheumatoid arthritis” (LORA); begins only after the age of 60.
- Juvenile rheumatoid arthritis (ICD-10: M08.-): is a chronic autoimmune disease of unknown etiology that occurs in childhood and adolescence; it is one of the most common chronic diseases in childhood.
- Still’s syndrome (synonym: Still’s disease; ICD-10: M08.2): systemic form of juvenile rheumatoid arthritis occurring in children with hepatosplenomegaly (liver and spleen enlargement), fever (≥ 39 °C, over 14 days), generalized lymphadenopathy (lymph node enlargement), carditis (inflammation of the heart), transient exanthema (skin rash), anemia (anemia). The prognosis of this disease is unfavorable.
- Caplan syndrome (ICD-10: M05.1-). Mixed dust silicosis of the lungs with numerous, rapidly developing round foci and temporally independent rheumatoid arthritis.
- Felty syndrome (ICD-10: M05.0-). Severe course of rheumatoid arthritis, almost always rheumatoid factor-positive, occurring mainly in men between the 20th and 40th year of life. Associated with hepatosplenomegaly (enlargement of the liver and spleen), leukocytopenia (decrease in the number of white blood cells/leukocytes) and thrombocytopenia (decrease in the number of platelets/platelets).
- Rheumatoid arthritis with secondary Sjögren’s syndrome. Approximately 20-30% of patients with rheumatoid arthritis develop xerostomia (dry mouth) and xerophthalmia (dryness of the eye).
Sex ratio: women to men is 2-3: 1. Frequency peak: age peak in childhood, between the 30th and 40th and after the age of 60. The maximum incidence of rheumatoid arthritis is between 55 and 64 years of age in women and between 65 and 75 years of age in men. The prevalence (disease incidence) is about 0.5-1% in developed countries. In Germany, the prevalence is 1.2%. The prevalence increases with age. From an age of > 55 years, it is 2 %. The incidence (frequency of new cases) for women is 34-83 cases per 100,000 inhabitants per year. Course and prognosis: The onset of the disease is often insidious, but can also be sudden. It is a chronic disease that usually progresses in relapses. An episode can last between a few weeks and months. The course of the disease depends largely on the time of onset, the severity of the disease or its course, and early therapy. Therapy should be started within the first 3 to 6 months of the disease, since this is the period during which the immunological process is most likely to be stopped or can be changed in the long term.Early, remission-oriented therapy ensures normal physical function without disability for 60-80% of patients. Comorbidities (concomitant diseases): Rheumatoid arthritis is associated (linked) with a greatly increased risk of arterial hypertension. One in three patients has this condition. Other comorbidities include degenerative joint disease, cardiovascular disease (heart disease), osteoporosis, and respiratory disease (see related conditions).
