Insect bite...ongoing symptoms???

My husband had a huge painful insect bite a few months back and did not know what bit him. A few weeks later he started saying that his knees were hurting really bad and this man never complains. Lately he's been breaking out in these rashes that are really itchy, never in the same place and disappear within 24 hours...has anyone any ideas? Could this be a reaction to that bite? It just seems like these where his complaints in the last 2-3 months and it seems to be getting worse.