Immune complexes deposition causing inflammation

Type 3 immune complex reaction Other drugs can form immune complexes with antibodies, IgG or IgM, which circulate in the blood and can be deposited in particular areas of the body, for example in the joints, skin or kidneys. See Figure 3.3c. Here the immune complexes can cause a local inflammation by activation of the complement system. 

Viral arthritis is rather common and usually selflimited within a few weeks. The most common pathophysiological mechanism is not a direct virus invasion in the synovium but deposition of immune complexes. Viral infections frequently involve multiple joints and produce inflammation without suppuration. The typical clinical presentation is a peripheral and symmetrical polyarthritis, undistin-guishable from other inflammatory arthritis. Virtually all viruses can cause arthritis. There is no specific treatment and simple symptomatic measures are sufficient. 

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