bumping the OP; extraarticular manifestations are common in RA (i.e. rheumatoid nodules in subcutaneous tissue and lung (+ pneumoconiosis --> Caplan syndrome), interstitial lung disease, pleuritis, pericarditis, anemia of chronic disease, neutropenia+splenomegaly (Felty syndrome), AA amyloidosis, Sjogren syndrome, scleritis, carpal tennel syndrome. (btw I thought RA was local and HSR II)
Serum sickness—the prototypic immune complex disease. Antibodies to foreign proteins are produced and 1–2 weeks later, antibody- antigen complexes form and deposit in tissues = complement activation = inflammation and tissue damage. Fever, urticaria, arthralgia, proteinuria, lymphadenopathy occur 1–2 weeks after antigen exposure. Serum sickness-like reactions are associated with some drugs (may act as haptens, eg, penicillin) and infections (eg, hepatitis B).