Diagnosis: Psoriatic Arthritis or Seronegative Spondyloarthropathy
This clinical presentation—gradual onset low back pain over 10 years, foot deformity, pain in fingers and toes, and hyperkeratosis—strongly suggests a seronegative spondyloarthropathy, most likely psoriatic arthritis or ankylosing spondylitis, rather than a primary mechanical or dermatologic condition. 1
Key Diagnostic Features
The constellation of symptoms points away from simple mechanical low back pain or isolated foot pathology:
- Chronic inflammatory back pain (10-year duration) in a patient without diabetes or hypertension suggests inflammatory rather than mechanical etiology 2
- Foot deformity with digital pain indicates inflammatory arthropathy affecting small joints 3
- Hyperkeratosis development is secondary to altered biomechanics from underlying joint disease and deformity 4, 3
- Family history of autoimmune disease (even if unreliable) raises suspicion for HLA-B27-positive spondyloarthropathy 1
Immediate Diagnostic Workup Required
This patient requires rheumatology referral and cannot be managed as simple mechanical back pain or podiatric hyperkeratosis alone. 1
Laboratory Testing
- HLA-B27 testing to evaluate for ankylosing spondylitis 1
- Inflammatory markers (ESR, CRP) to assess disease activity 2
- Rheumatoid factor and anti-CCP antibodies to differentiate from rheumatoid arthritis 1
Imaging Studies
- MRI of lumbar spine without contrast is the preferred modality to evaluate for inflammatory changes, sacroiliitis, and structural abnormalities 5
- Plain radiographs of hands and feet to assess for erosive changes and joint space narrowing characteristic of psoriatic arthritis 1
Treatment Approach
Primary Disease Management
The underlying inflammatory arthropathy must be treated first, as symptomatic foot care alone will fail without addressing the systemic disease. 1
- Rheumatology consultation for initiation of disease-modifying therapy (DMARDs or biologics) is the priority 1
- NSAIDs may provide temporary symptom relief but do not address disease progression 2
Symptomatic Foot Care (Adjunctive Only)
While awaiting rheumatology evaluation, conservative podiatric management can provide temporary relief:
Hyperkeratosis Management
- Conservative scalpel debridement by trained podiatrist, avoiding overdebridement which can worsen pain 2, 6
- Debridement reduces pain and improves functional ability in older adults with plantar hyperkeratosis 6
- Apply emollients and protective dressings after debridement 2
- Pressure redistribution with cushioning insoles to prevent hyperkeratosis recurrence 2
Footwear Modifications
- Supportive, well-fitted shoes with adequate depth to accommodate foot deformities 2
- Custom orthotics or molded insoles to redistribute plantar pressures away from deformed joints 2
- Pressures exceeding 400 kPa under metatarsal heads predict hyperkeratosis development 4
Back Pain Management (Chronic)
For the 10-year history of low back pain, while inflammatory causes are being evaluated:
- Exercise therapy, acupuncture, or spinal manipulation have moderate evidence for chronic low back pain 2
- Cognitive-behavioral therapy may help with chronic pain management 2
- Avoid long-term opioids or systemic corticosteroids, which lack efficacy for inflammatory back pain 2
Critical Pitfalls to Avoid
Do not treat this as isolated mechanical back pain or simple calluses. 1 The gradual progression over 10 years with multi-joint involvement demands systemic evaluation. Treating only the hyperkeratosis without addressing underlying inflammatory arthropathy will result in continued disease progression, worsening deformity, and functional decline 1, 3.
Do not delay rheumatology referral. Early diagnosis and treatment of seronegative spondyloarthropathies significantly impacts long-term outcomes, preventing irreversible joint damage and spinal fusion 1.
The hyperkeratosis is a consequence, not the cause of this patient's problems—it develops from altered biomechanics secondary to joint deformity and inflammation 4, 3. Addressing only the skin manifestation ignores the progressive systemic disease requiring immunomodulatory therapy 1.