Secondary (acquired) Knuckle Pads

Carsten Sauer Mikkelsen | Kesä 2020 | Reumasairaudet |

Carsten Sauer Mikkelsen
Specialist in Dermato-venereology,
Private Practice in Dermato-venereology,
Brønderslev, Denmark
& Research lab.
Department of Dermato-venereology,
Aalborg University Hospital, Denmark

Kristian Bakke Arvesen
Specialist in Dermato-venereology,
Research lab.
Department of Dermato-venereology,
Aalborg University Hospital, Denmark

Luit Penninga
Specialist in Surgery,
Ilulissat Hospital,
Avannaa Region,
Ilulissat, Greenland

Peter Bjerring
Specialist in Dermato-venereology,
Research lab.
Department of Dermato-venereology,
Aalborg University Hospital, Denmark

Background A 68-year-old otherwise healthy patient who had engaged in cobblestone paving all his working life came to the clinic for examination of the knuckles on his right hand. He presented skin coloured, painless local swellings over the 3+4+5 metacarpophalangeal (MCP) joints on his right hand. While recording the patient’s history, we asked about repetitive traumas as a clue to the diagnosis. He told about his daily job and described the repetitive external frictional pressure/trauma when he positioned the cobblestones in the right place.He only used his right hand for this purpose. The expanded family history was uninformative, with no hereditary Dupuytren's contracture. The patient's medical history was otherwise unremarkable and did not suggest a predisposition to a specific musculoskeletal disorder. He reported no morning stiffness, no paraesthesia and no pain during the night or other signs for inflammatory or mechanically induced pain. We had no suspicion of any psychiatric disturbances that could have given rise to repetitive compulsive behaviour like biting or chewing on the nodules. Clinical presentation Clinical examination showed several soft subcutaneous nodules located on the dorsal aspect of the MCP joints of the third, fourth and fifth fingers on his right hand (figure 1). There was no local tenderness and the overlying skin showed a normal temperature. The nodules were not adherent to the joint capsule. There were no signs of synovitis or tendosynovitis, thickening of the palmar fascia or muscle atrophy. Local neurological examination was normal. The skin overlying the other joints of the hand and nails was normal. Since the reason for his knuckle pads (KPs) was obvious we did not perform a biopsy or ultrasound examination. A rheumatological examination excluded any inflammatory joint disease. All blood tests, including ANA-hep2-screening, anti-CCP, and IgM-RF, were normal. Discussion Knuckle pads, also known as “Garrod's nodes”, are...