Images Clinical: Acro‐osteolysis: a complication of systemic sclerosis or rheumatoid arthritis?

Abstract

The patient, a 63-year-old woman, was seen in the rheumatology clinic for anti-ribonucleoprotein (RNP) negative overlap syndrome (systemic sclerosis [SSc] and high-titre dual-seropositive rheumatoid arthritis [RA]), manifesting as Raynaud syndrome, sclerodactyly, interstitial lung disease, and synovitis. On examination, synovitis was palpated at the right second metacarpophalangeal joint, sclerodactyly was appreciated distal to metacarpophalangeal joints bilaterally, and there was striking fingertip pulp atrophy without any gangrene (Figure 1A). Nailfold capillaroscopy revealed dilatations and dropout. Hand radiographs (Figure 1B) revealed an erosion (white arrow), a distal tuft acro-osteolysis (blue arrows), and a band acro-osteolysis (red arrows). Acro-osteolysis, the absorption of distal bony phalanges, can be radiologically classified as either distal tuft, band, or combined (1). Isolated band pattern occurs in polyvinyl chloride (PVC) exposure, and isolated distal-tuft pattern can be appreciated commonly in SSc, Raynaud syndrome, thermal injury, dermatomyositis, and hyperparathyroidism. Rarely, the isolated tuft pattern can be seen in arthritides (like RA, psoriatic arthritis, and erosive osteoarthritis) with extension of destruction distally from the distal interphalangeal joint (2). The combined pattern occurs in SSc and hyperparathyroidism. The clinical quandary in our patient is that the acro-osteolysis could be from either RA or Raynaud syndrome. However, in the presence of both distinct tuft and band patterns, poorly controlled Raynaud syndrome was the likely culprit for acro-osteolysis rather than the rarely associated RA. Disclosure Form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.