[Meningococcal infection and arthritis].

Arthritic manifestations in patients with meningococcal disease are of varied pathogenesis. Four different pathogenic mechanisms may be involved. Direct bacterial invasion of the synovium and multiplication within the joint (septic arthritis); hypersensitivity reaction or allergic arthritis; intra- or periarticular hemorrhage (hemarthrosis) and iatrogen causes, i.e. reaction to antimicrobial agents, serum therapy etc. Four distinct clinical forms have been described: The septic, culture-positive polyarthritis is seen early in the course of the disease. The sterile "non-infectious" or allergic mono- or oligo arthritis are seen later in the course. Primary meningococcal arthritis. Arthritis may be seen in relation to chronic meningococcemia. Treatment consists primarily of specific antimeningococcal chemotherapy, viz penicillin and non-steroid-anti-inflammatory drugs. The prognosis of meningococcal arthritis is excellent and joint sequelae are rare. Predisposing factors in relation to meningococcal disease are reviewed. The most important are socioeconomic conditions, acute respiratory illness, particularly in relation to age as children less than two years are most susceptible, passive smoking, IgA blocking antibodies, the concentration of complement factors C3, C6, C7, C8, and IgG2-defects.