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A 51 year old factory worker presented with a two year history of pain and swelling of the right index and middle finger metacarpophalangeal (MCP) joints. He had no significant past medical history and there was no family history of arthritis. Examination showed bony deformity and diminished range of movement at the right index and middle MCP joints. The left hand and other joints were normal. There were no abnormalities on examination of his cardiovascular system or abdomen.
His job in a car assembly factory for the previous 10 years had involved lifting mesh car components from a container using only his right hand, and he estimated that he would carry out this manoeuvre about 4000 times in a day.
Radiographs of his right hand showed joint space narrowing and osteophytes at the right second and third MCPs (fig 1A). The left hand was radiologically normal (fig 1B).
His rheumatoid factor, blood count, and erythrocyte sedimentation rate were negative/normal. Serum alkaline phosphatase was 150 U/l (normal 30–130). Fasting glucose was 5.8 mmol/l. Serum ferritin was 1184 ng/ml (normal 20–350) with a serum iron of 42 μmol/l (normal 14–31) and transferrin saturation 80% (normal 20–30). Genetic studies showed him to be homozygous for the Cys282 Tyr mutation, the genotype found in over 90% of patients with haemochromatosis in the UK. He was diagnosed with haemochromatosis and treated by venesection.
His family members have been screened for the condition. One son aged 29 years has been found to have a transferrin saturation of 60%. Ferritin level is normal. Genetic testing has been carried out and shown him to be a compound heterozygote with Cys282 Tyr and His 63 Asp mutations, a genotype associated with haemochromatosis in 20% of cases. He is at present being kept under surveillance.
There have been reported cases of undiagnosed haemochromatosis presenting as exercise related joint pains in recreational runners with underlying haemochromatosis arthropathy.1 However, this patient's unilateral arthritis suggests that minor trauma may interact with genetic haemochromatosis to determine the distribution of joint damage. This is consistent with the observation of Lee et al, who described unilateral arthropathy on the normal side of a patient with haemochromatosis and a hemiparesis.2
Whether the course of arthritis is altered by venesection is unclear. However, it is important to make an early diagnosis of haemochromatosis in a patient presenting with arthropathy because venesection may prevent internal organ damage.