In the case of our patient, the inflammatory arthritis and dactylitis affecting the right hand developed in temporal proximity to a significant injury. There have been earlier case reports in the English-language literature of posttraumatic development or exacerbation of both seronegative and seropositive inflammatory arthropathies, which are summarized in .1–11
These reports exhibit varying degrees of temporal or physical proximity to the recalled injury. There have also been 2 case studies of patients with psoriatic skin disease who developed terminal acroosteolysis after a local traumatic event affecting the nails but without apparent articular involvement.12,13
Additionally, there have been several instances of posttraumatic initiation of inflammatory arthropathies reported in the non–English-language literature.3
These various individual histories are intriguing and assist in generating hypotheses; however, they are insufficient in themselves to unequivocally assign causality.
Case reports of posttraumatic development or exacerbation of both seronegative and seropositive inflammatory arthropathies
The cases described in 1–11
include seropositive rheumatoid arthritis, arthropathies associated with HLA-B27 positivity, reactive arthritis, and psoriasis-associated arthritis. Of the 22 cases detailed, 10 were associated with psoriatic or psoriaticlike skin lesions.
The concept of trauma as an inciting event in psoriatic arthritis seems to have originally arisen from the observation in the dermatology population of a Köbner phenomenon, whereby development of psoriatic skin disease has been observed at the sites of significant injury to the dermis and epidermis. It has been proposed that psoriatic arthritis after injury might reflect a “deep-Köbner” effect.12
To further evaluate the premise that trauma might be an inciting event in psoriatic arthritis, Scarpa et al undertook a retrospective chart review of the medical records of 138 patients with psoriatic arthritis and 138 patients with rheumatoid arthritis. A preceding acute event was documented in 9% of patients with psoriatic arthritis in the 10 days before onset of joint symptoms, compared with 1% of patients with rheumatoid arthritis. A preceding event was not found to be more common in patients with psoriatic arthritis who had positive HLAB27 status.14
Two recent retrospective case-control studies have been conducted to evaluate frequency of preceding trauma in patients with psoriatic arthritis. Thumboo and colleagues employed the Rochester Epidemiology Project database, securing 60 psoriatic arthritis cases and 120 control patients with psoriasis. Trauma
was defined as documented motor vehicle accident, fracture, sprain or contusion, surgical procedure, or burn. The time frame extended to 2 years before onset of joint symptoms. There were no significant differences observed in odds ratios for either fractures or all forms of trauma between the psoriatic arthritis cases and the control group.15
The second case-control study was reported by Pattison et al and examined a UK population of 98 psoriatic arthritis cases and 163 control patients with psoriasis. Patients who developed psoriatic arthritis onset within 5 years of the selected study date were included. Physical trauma
was defined as documented road traffic accidents, fractures, or other injuries requiring treatment by a general practitioner or at an accident and emergency department in the previous 10 years before the study date. The strongest association was with “trauma leading to medical care,” which applied to 14.9% of cases and 7.9% of controls for an odds ratio of 2.53 (95% CI 1.1 to 6.0).16
The multifaceted pathogenesis of psoriatic arthritis is an area of ongoing study. Evidence of genetic contribution predisposing to development of arthritis has been found in specific HLA allele associations and in identification of susceptibility genes.17
Support for a possible dysregulation of the innate immune response, particularly to bacterial antigenic stimulation, has also been reported.17
In terms of tissue-specific factors, recent persuasive work by McGonagle et al suggests the enthesis might be a key site for initiation of psoriatic arthritis, with enthesitis or osteitis preceding development of adjacent synovitis and joint damage.18,19
Enthesitis might be provoked by repeated microtrauma from shear and compressive stressing or by a more substantial single injury.