Rare presentation of bilateral thumb psoriatic arthritis treated with arthrodesis: a case report

Psoriatic arthritis (PsA) is a seronegative inflammatory arthritis that occurs concomitantly with cutaneous manifestations and tendinous pathology that affects up to 1% of the general population. While the majority of cases are mild, nearly 20% of PsA patients will progress to severe disease manifesting as debilitating polyarticular inflammation and joint destruction. PsA is most commonly asymmetric and bilateral severe disease involving the same joints in each hand has rarely been reported in the literature. It is estimated that PsA only presents bilaterally in a quarter of patients. The recent increase in popularity and efficacy of disease-modifying anti-rheumatic drugs (DMARDs) has led to increasing rarity of such severe disease progression. We present a case of a 47-year-old male with PsA who had a unique pattern of bilateral first metacarpophalangeal (MP) and interphalangeal (IP) involvement with minimal erosion leading to significant joint pain, instability, dislocation, and loss of function. After failure of conservative treatment that included both DMARDs and non-steroidal anti-inflammatory drugs (NSAIDs), the patient opted for surgical management. The purpose of this report is to identify a rare presentation of PsA and consider the significance of MP joint arthrodesis as a viable treatment to restore functional status and improve quality of life.