Mathes, E.F.D., et al. - The triad of fever, rash, and arthritis in a hospitalized child suggests an inflammatory, infectious, or postinfectious process in most cases; however, malignancy must be considered. The most common causes in this age group are inflammatory conditions, including Kawasaki disease, Henoch-Schonlein Purpura, serum sickness-like reaction, and juvenile idiopathic arthritis. Other rarer inflammatory processes can present with this triad of symptoms such as Cryopyrin-related diseases (autoinflammatory disorders), urticarial vasculitis, and systemic lupus erythematosus