Erosive hand osteoarthritis and systemic sclerosis: a casual association?

To describe an unexpected association between a patient affected with erosive hand osteoarthritis (EHOA) and systemic sclerosis (SSc). We report a case of SSc presenting typical radiological findings of EHOA in a 60-year-old woman referred to our outpatient Rheumatology Unit. Physical examination revealed puffy hands with sclerodactyly and concomitant adduction of the thumb and subluxation of the first carpometacarpal (CMC) and metacarpophalangeal (MCP) joints bilaterally and nodose deformities of the distal interphalangeal (DIP). Hand X-rays showed joint space narrowing, osteophytosis and bone sclerosis of the proximal interphalangeal (PIP) joints. The DIP joints showed central bone erosion, collapse of the subchondral bone plate and typical "gull-wing" type deformity. EHOA is a particularly aggressive subset of osteoarthritis (OA). In light of its still unclear pathogenesis, peculiarities in the disease characteristics may be useful to better define the EHOA patient profile. One of these is an unexpected association with some autoimmune diseases. EHOA and SSc in the same patient is not uncommon, and it could speculate that there may be a genetic and autoimmune involvement.