Background Foot complaints are common in inflammatory arthropathies such as rheumatoid arthritis and cause considerable disability. However, little is published about the nature and extent of foot complaints in systemic lupus erythematosus (SLE).
Objectives The objective is to explore clinical features and symptoms of foot involvement in people with SLE from the patients' perspective.
Methods We developed and tested a new 40-item item self-administered questionnaire, using a five-stage development process utilising patient involvement throughout to ensure face and content validity. The self-administered instrument was posted to 406 people with SLE attending adult rheumatology clinics across three health boards in Auckland, New Zealand. The questionnaire enquired about symptoms of foot pain, extra-articular features, anatomical distribution of symptoms according to validated foot-mannequins and the impact of foot symptoms on activities of daily living and well-being
Results From 131 responses (32% response rate), 89% women, mean (SD) age 51 (15.1), mean (SD) disease duration 12.5 (11.1) years. 77.1% respondents experienced foot pain during the course of their lupus, 51.9% reporting pain in the last month and 45% reporting current foot pain. The mean (SD) score on a 10cm visual analogue scale for current foot pain was 4.9 (2.2). There was no association between foot pain and the following variables: age, duration of SLE, body mass index, ethnicity, work status or smoking. Females were significantly more likely to report foot pain (p=0.028) and being female was a risk factor for foot pain independent of all other demographic variables (OR 1.78 [95%CI 0.62-2.98]). All regions of the feet were affected, with the hindfoot and ankle most frequently affected during the course of the disease (32% and 30% respectively). Respondents reported foot pain prevented sleep for 36% and 33% reported pain in their feet had a negative effect on their emotions. Life in general was adversely affected by foot pain with 60% reporting limitation in foot-related activities of daily living (e.g. walking). Taken together, 70% of respondents reported foot problems that interfered with social activities and 60% reported foot complaints that interfered with their family activities
Conclusions Foot symptoms in SLE are common, heterogeneous in nature and may have a negative impact on patient well-being.
Acknowledgements We thank respondents for thier time in completing the questionnaire and our research assistants - Jemma Crawley, Hilary Otter and Heather Waddington
Disclosure of Interest None declared