Diagnostic confusion caused by hepatitis C: hemochromatosis presenting as rheumatoid arthritis.

We describe a patient with hemochromatosis and coexistent infection with the hepatitis C virus who was initially thought to have rheumatoid arthritis. His symptoms began at the age of 44 with pain of the hand joints, shoulders, hips, and knees and a positive rheumatoid factor. Four years later, he required replacement of both hips due to severe hip arthritis. Abnormalities in liver function were noted early on, but they were attributed to infection with the hepatitis C virus, detected serologically and by polymerase chain reaction amplification in the blood. The correct diagnosis was delayed until a decision to use methotrexate as treatment for his arthritis led to a liver biopsy, which revealed increased iron deposition consistent with hemochromatosis, confirmed by genetic testing, which revealed that the patient was homozygous for the C282Y mutation of the HLA-H gene.