History and admission findings: A 42-year-old woman, with recurrent arthritis of the large joints and erythema nodosum for 7 years, was admitted because of recent onset of bouts of rapid heart rate. A 2/6 systolic murmur at Erb's point was the only contributory finding on physical examination.
Investigations: The transaminases and gamma-GT were elevated, as were total cholesterol, LDL fraction, IgM, total protein, gamma-globulin and IgM. Antimitochondrial antibodies, especially anti-M2, were positive, while rheumatoid factor and C-reactive protein were negative. ANA, ANCA and antibodies against double-strand DNA were not demonstrated. ENA screening was negative. Abdominal computed tomography showed discrete intrahepatic cholestasis. Liver biopsy revealed chronic destructive cholangitis, i.e. the early stage of primary biliary cirrhosis.
Treatment and course: On treatment with ursodeoxycholic acid (10 mg/kg daily) the patient has remained free of symptoms for 3 years and laboratory tests no longer showed evidence of impaired liver function.
Conclusion: Primary biliary cirrhosis should be included in the differential diagnosis of recurrent arthritis and erythema nodosum, as early treatment with ursodeoxycholic acid can favourably influence its course.