Disabling foot pain in PsA: Marker of worse PsA, significant burden on daily life

For Singaporeans with psoriatic arthritis (PsA), disabling foot pain (DFP) appears to signal a more severe disease activity and exert a wide impact on daily life.

In a cross-sectional, retrospective study, all global measures and disease indices were significantly higher among PsA patients with vs without DFP (p<0.05), except for erythrocyte sedimentation rate (p=0.56) and C-reactive protein measures (p=0.78). [BMC Rheumatol 2024;8:52]

“Significant differences between groups were also observed in the SJC-66 and TJC-68. There was a much higher proportion of swollen and tender joints in the foot and ankle in those with DFP compared to those without, which suggests that the inclusion of extended joint counts can potentially identify those with higher levels of foot-disease burden in people living with PsA,” the investigators noted. [Ann Rheum Dis 2012;71:830-835]

Furthermore, patients with DFP had reduced physical function (mean MD-HAQ* score of 0.5 vs 0.2), higher levels of global pain (mean numeric rating scale score, 4 vs 2), higher musculoskeletal disease activity (mean RAPID3** score, 10.6 vs 5.6), and poorer health-related quality of life (mean EQ-5D-3 L VAS⁺ score, 57.3 vs 65.8) relative to those without DFP.

“Overall, the most frequent concerns were walking slowly, difficulty with prolonged standing/walking, and undertaking daily routines with more pain,” the investigators noted.

Despite a greater proportion of patients with DFP working full-time (68 percent vs 32 percent) and spending longer than 3 hours per day on their feet (23 percent vs 13 percent), around one-third of them (36 percent) reported being unable to perform their previous jobs as opposed to none in the no-DFP group. Walking 3 km proved significantly more difficult for patients with DFP (p<0.05).

The study population comprised 42 patients with PsA (mean age 42 years, 83 percent female, 57 percent Chinese), with a median disease duration of 2 years and all of them taking disease modifying anti-rheumatic drugs. Seventeen patients had DFP (40.5 percent), with the most common cause being rearfoot enthesitis (67 percent). Most patients (72 percent) were overweight or obese and did not engage in any cardiovascular exercise (70 percent). Seventy percent of patients engaged in sedentary or light leisure activities, such as watching TV, gaming, or sewing.

Most patients (90 percent) reported coping well with their condition, citing self-care and having emotional support as key factors. Nevertheless, there was a high prevalence of anxiety/depression (29 percent), sleep disturbance (34 percent), and fatigue (24 percent). More than half of the population also lacked disease- and drug-specific knowledge (64 percent). Only three patients had previously seen a podiatrist.

“This study demonstrates that DFP in PsA negatively impacts on the daily lives of people in Singapore including their walking ability, participation in exercise and leisure activities, and ability to perform household and work tasks,” the investigators said.

“Lower levels of exercise in those with DFP indicate that foot problems and the consequent gait function deficiencies are potential barriers to physical activity and may be contributing to major health issues for people with PsA. This is an important observation from our study as those individuals represent a high-risk group for adverse cardiovascular health,” they continued.

The investigators called for additional research to determine the potential benefits of a multidisciplinary approach to increasing activity levels. This approach may include “a targeted educational program on the benefits of exercise tailored to people with PsA to improve disease-specific understanding; prescription of exercise therapy; and interventions that address biomechanical abnormalities in the foot to reduce mechanically triggered inflammation and pain in people with PsA with disabling foot problems.”