Seasonal variation of rheumatic diseases.

Extract: Seasonal variation has been shown in a number of rheumatic diseases (diseases involving the joints and related structures). The incidence of acute gouty attacks (an inflammatory arthritis) is highest in the spring. The onset or exacerbation of rheumatoid arthritis, the onset of Wegener's granulomatosis (chronic tissue inflammation and cellular clumping in the nasal passages, lungs and kidneys), anti-neutrophil cytoplasmic antibodies (ANCA) associated kidney inflammation (glomerulonephritis) and systemic vasculitis are all seen more commonly in the winter. There is a significant increase in the incidence of positive biopsies in giant cell arteritis (vascular inflammation of the temple) in late winter and autumn. In systemic lupus erythematosus (SLE, an autoimmune disease in which antibodies to self components are found in the blood stream and in tissues) there may be a tendency for different organs to be affected during different seasons. In SLE patients, there is an increased incidence of photosensitive skin rashes in the summer and of joint pain in the winter and spring. A significantly higher prevalence in the winter and spring was observed among SLE patients with class V lupus nephritis (LN, inflammation of the kidneys), as compared with the summer and fall. A similar trend was seen for seasonal variation of the percentage of class III lupus nephritis patients.