Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Rheumatic fever occurs after untreated streptococcal infections (e.g. strep throat) mostly in children. It is characterized fever, join pain and swelling, skin nodules (on elbow or knees) and rashes, and heart problems. Joint pain in rheumatic fever has characteristic migratory nature i.e. pain spreads from one joint to another. Yes, rheumatic fever mostly affects children but can affect people at any age. Elderly can be affected very rarely. If your husband did not have throat pain or skin infections recently rheumatic fever is highly unlikely. Furthermore, rheumatic fever is very rare in developed countries. He is most likely suffering from other joint problems, highly likely from osteoarthritis. The diagnosis can be confirmed with physical exam, blood tests and knee X-ray. Hope I have answered your query. Let me know if I can assist you further. Thank you.