Haemochromatosis: unexplained metacarpophalangeal or ankle arthropathy should prompt diagnostic tests: findings from two UK observational cohort studies.

OBJECTIVES: To examine demographic and clinical features leading to the diagnosis of hereditary haemochromatosis and assess factors that might enhance earlier diagnosis, with particular attention to arthritic symptoms.

METHOD: Diagnostic features were captured directly from patients with haemochromatosis attending a specialist rheumatology clinic (group 1) and from analysis of a specifically designed questionnaire circulated to members of the UK Haemochromatosis Society (group 2).

RESULTS: In groups 1 (n = 62) and 2 (n = 470), respectively, the diagnosis of haemochromatosis was made at a mean age of 52.8 and 56.4 years with 77% and 76% reporting joint symptoms with a mean duration of 8.3 and 8.1 years. The first joints to be affected in group 1 were the metacarpophalangeal (MCP; 38.5%) and ankle (29.5%) followed by the knee, hip, and proximal interphalangeal (PIP) joints. At the time of clinical assessment or questionnaire completion, the most prevalent regions with arthropathy in group 1 were PIP (64.5%), knee (64%), ankle (61%), and MCP (60%) and in group 2 the most prevalent joint regions self-reported were the first carpometacarpal (CMC; 59%), wrist (52%), PIP (47%), MCP (46%), knee (42%), and ankle (35%).

CONCLUSIONS: Data from both cohorts confirm the high prevalence of joint symptoms in haemochromatosis predating the diagnosis by many years. Discriminatory features of the arthropathy include the involvement of MCP joints and ankles at a relatively young age in the absence of trauma, all of which are unusual features of primary osteoarthritis (OA). The finding of this presentation should prompt diagnostic tests for haemochromatosis.