What causes foot pain in patients with Systemic Lupus Erythematosus (SLE)?

Why Feet Hurt with Lupus

Foot pain in systemic lupus erythematosus (SLE) occurs primarily due to inflammatory arthritis affecting the ankle and hindfoot joints, vascular insufficiency from Raynaud's phenomenon, peripheral neuropathy causing numbness and pain, and extra-articular manifestations including cold sensitivity and swelling. 1, 2

Primary Mechanisms of Foot Pain in SLE

Musculoskeletal Inflammation

• Arthritis and arthralgia are the most common causes of foot pain in lupus, affecting up to 77% of patients during their disease course, with 45% experiencing current foot pain at any given time. 2
• The hindfoot (32%) and ankles (30%) are the most frequently affected anatomical regions, causing pain that interferes with standing, walking, and climbing stairs. 2
• Joint inflammation in SLE is typically episodic and self-limited, but can become chronic and refractory in some patients, requiring escalation beyond NSAIDs. 3

Vascular Manifestations

• Raynaud's phenomenon affects the feet in SLE patients, though less commonly than hands, causing cold-induced vasospasm that leads to pain, color changes, and delayed reperfusion. 4
• Cold feet and swelling are among the most common self-reported extra-articular foot complaints in SLE. 2
• Vascular insufficiency can contribute to tissue ischemia and pain, particularly in cold environments. 4

Neurological Involvement

• Peripheral neuropathy causes numbness, burning sensations, and neuropathic pain in the feet of lupus patients. 2
• Neurological involvement occurs frequently in SLE and can manifest as sensory loss or painful paresthesias affecting the lower extremities. 4

Chronic Widespread Pain

• Fibromyalgia coexists with SLE in a substantial proportion of patients, causing diffuse musculoskeletal pain including the feet that is independent of disease activity. 5
• This chronic widespread pain interferes with daily activities and must be distinguished from inflammatory pain to avoid dangerous over-treatment with immunosuppression. 5

Impact on Function and Quality of Life

• Foot pain in lupus significantly impairs activities of daily living, with strong associations between foot pain and inability to stand longer than 15 minutes (p<0.001), walk (p<0.001), climb stairs (p<0.001), and shop (p<0.001). 2
• 61% of SLE patients report that foot pain adversely affects their lives, with 36% experiencing sleep disruption and 33% reporting negative emotional effects. 2
• Pain is the primary symptom affecting quality of life in SLE patients with foot complaints, rating 47/100 on impact scales. 2

Clinical Recognition and Management Gaps

• Most lupus patients "self-treat" foot problems rather than seeking professional podiatric care, with only 33% having seen a podiatrist despite the high prevalence and impact of foot complaints. 1, 2
• Patients perceive that foot health is not within the rheumatologist's role during medical consultations, leading to underreporting and undertreatment of foot problems. 1
• There is a critical need for feet to be included as part of routine patient monitoring in SLE, as foot complaints are heterogeneous and substantially reduce daily activity. 1, 2

Treatment Approach for Lupus-Related Foot Pain

Foundation Therapy

• Hydroxychloroquine at ≤5 mg/kg real body weight is mandatory for all SLE patients as it reduces disease activity, prevents flares, and serves as the cornerstone for managing musculoskeletal symptoms including foot pain. 6, 7

Acute Musculoskeletal Pain

• NSAIDs are first-line for intermittent foot and ankle joint pain, with up to 80% of lupus patients receiving them for musculoskeletal symptoms. 6, 3
• For severe acute flares, intravenous methylprednisolone pulses (250-1000 mg daily for 1-3 days) provide immediate relief and enable lower starting doses of oral glucocorticoids. 6, 7

Chronic or Refractory Foot Pain

• Low-dose glucocorticoids (≤7.5 mg/day prednisone equivalent) combined with hydroxychloroquine for persistent pain, with the goal of minimizing chronic steroid exposure. 6, 7
• For corticosteroid-dependent arthritis requiring unacceptable doses, methotrexate should be added initially in combination with antimalarial drugs. 3
• Corticosteroid infiltrations may be useful for persistent localized ankle or foot arthritis. 3

Orthotic Interventions

• Both custom-made functional foot orthoses and flat cushioning insoles reduce foot pain in SLE patients, with pain scores decreasing from 6.8 to 4.2 over 90 days with custom orthoses and from 6.5 to 4.7 with cushioning insoles. 8
• Providing cushioning to the foot has positive effects on managing foot pain, suggesting that mechanical support is beneficial regardless of the specific orthotic type. 8

Physical Exercise

• Physical exercise should be considered for all SLE patients (Level of Evidence 1-3) as it improves fatigue and aerobic capacity based on multiple meta-analyses of randomized controlled trials. 4

Common Pitfalls to Avoid

• Do not attribute all foot pain to active lupus inflammation—consider coexisting fibromyalgia, which requires different management and does not respond to immunosuppression. 5
• Do not overlook vascular assessment—examine for Raynaud's phenomenon and peripheral arterial disease, as these require specific interventions beyond anti-inflammatory therapy. 4
• Do not ignore patient reports of foot problems during routine visits—actively inquire about foot symptoms as patients often fail to disclose them spontaneously. 1
• Do not prescribe chronic high-dose glucocorticoids for foot pain alone—this leads to organ damage and should be avoided by promptly adding steroid-sparing immunomodulatory agents. 6, 7