Background: Peripheral small joint arthritis, dactylitis, enthesitis and skin and nail changes are well recognised localised features of PsA in the foot . However, relatively little is known about the burden of foot involvement in terms of impairment and related disability or provision of conservative and surgical care.
Objectives: To evaluate the burden of foot related problems and foot care provision in patients with PsA.
Methods: Sixty five PsA patients (26 male, 39 female) with a mean age of 52 years and disease duration of 10.8 years were consecutively recruited from rheumatology outpatient clinics at the Glasgow Royal Infirmary. A single specialist podiatrist conducted a foot examination documenting features of dactylitis and joint and soft-tissue pain and tenderness. Foot deformity and function was evaluated using the Structural Index . Self-reported foot pain was also recorded. The burden of foot disease was measured using the Leeds Foot Impact Scale (LFIS) impairment/footwear (LFISIF range 0-21) and activity limitation/participation restriction (LFISAP range 0-30) subscales of the Leeds foot impact scale. History of previous conservative or surgical foot care was also recorded.
Results: A high proportion of patients (65%) had self reported foot pain. Forefoot deformity (hallux valgus/claw toe) was found in 95% of patients and rearfoot deformity (pes planovalgus) was found in 65% of patients. 20% of patients were found to have dactylitis. Localised tenderness and/or swelling indicating inflammatory involvement was found at the Achilles tendon in 17%, plantar fascia in 20%, peroneal tendons in 22% and posterior tibial tendon in 34% of patients. Joint tenderness was detected in one or more metatarsophalangeal joints in 45% and interphalangeal joints in 31% of patients. The mean LFISIF score was 9.5 (range 0-19) and the LFISAP was 14.3 (range 0-30). 68% of patients were managed on Disease Modifying Antirheumatic Drugs (DMARD) and 11% on biologic therapy. Conservative or surgical foot care had been provided in 24% and 6% of patients respectively.
Conclusion: High levels of self-reported foot pain and deformity were found in this group. PsA appears to significantly impact on the structure and function of the foot with clinically important levels of impairment and related disability reported. The overall burden of foot disease was similar to those reported for other inflammatory joint diseases, notably rheumatoid arthritis. The level of foot care provision relative to the frequency and severity of foot problems appears discordant and merits further investigation.