Soft-tissue swelling around the proximal interphalangeal joints bilaterally: pachydermodactyly

Pachydermodactyly presenting as juvenile idiopathic arthritis in an adolescent man

We present the case of a 17-year-old Asian man diagnosed with pachydermodactyly, a rare digital fibromatosis. Although this is a non-inflammatory periarticular soft tissue disorder, the clinical appearance can mimic inflammatory arthritis. The patient had a 2-year history of fusiform swelling of multiple proximal interphalangeal joints. He was initially diagnosed with juvenile idiopathic arthritis and treated with methotrexate, but a lack of clinical response led to the diagnosis of pachydermodactyly. Recognising this rare condition can prevent unnecessary and potentially harmful treatment.

Pachydermodactyly: a systematic review

INTRODUCTION/OBJECTIVES

Pachydermodactyly is a rare, benign fibromatosis located around the proximal interphalangeal joints. It is often misdiagnosed as juvenile idiopathic arthritis and may cause unnecessary treatments and anxiety in patients. The goal of this paper is to describe this condition through all the existing information in the scientific literature.

METHOD

A systematic review and a descriptive study have been conducted. A systematic research was performed in PubMed, Embase, Cochrane Library and WOS.

RESULTS

Pachydermodactyly was four times more frequent in male subjects and usually started in adolescence. Bilateral presentation was more frequent. History of microtrauma in both hands due to digital manipulation was found in almost half of the patients, many of them showed some neuropsychiatric disorder. In women, the onset happened later, unilateral involvement and family history were more frequent. Swelling of soft tissue without joint implication was found in imaging tests. The progression was usually positive and the treatment included stopping the microtrauma, administrating intralesional corticoids and/or surgery.

CONCLUSIONS

Diagnosis can be established in asymptomatic young patients through a congruent physical exam, regular analytic results and imaging tests that simply show swelling of soft tissue-a biopsy is generally not required for diagnosis. As pachydermodactyly's course is asymptomatic and benign, knowledge about this condition is limited, which increases the likelihood of its underdiagnosis-it is important that clinicians know of pachydermodactyly in order to avoid misdiagnosis.

Pachydermodactyly: a review

Synovitis is the characteristic feature of inflammatory joint disease. If synovitis is localized to interphalangeal joints, rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis are among the most common differential diagnoses. The absence of pain, tenderness, and limitation of function despite progressive swelling of proximal interphalangeal joints suggests an alternative diagnosis, for example pachydermodactyly (PDD). This is a benign disease, associated with asymptomatic, progressive swelling of periarticular soft tissue, which usually occurs in young males. PDD is probably the result of repetitive mechanical stimulation. One hundred and twenty-one cases have been reported in the literature. Some of these were initially misdiagnosed and treated for inflammatory arthritis. We provide a comprehensive review of the literature on pachydermodactyly to promote awareness of this rare but important differential diagnosis of arthritis.