Rheumatoid arthritis--1: clinical features.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001171:Arthritis, Juvenile / Q000175:diagnosis; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000473:pathology; D002648:Child; D006801:Humans; D008875:Middle Aged