Rheumatologic Conditions affecting the Foot

Aka: Rheumatologic Conditions affecting the Foot, Foot associated Rheumatologic Conditions, Foot Arthritis

1. See Also
   1. Heel Pain
   2. Foot Pain
   3. Foot Anatomy
   4. Foot Dermatitis
2. Imaging
   1. Plain Radiographs (AP, Lateral and Oblique): Preferred first-line test
   2. See Joint Imaging in Rheumatoid Arthritis
   3. See Joint Imaging in Osteoarthritis
3. Findings: Degenerative Arthritis (Osteoarthritis)
   1. First MTP joint commonly involved
      1. Associated with Hallux Valgus deformity
      2. Associated with Hallux Rigidus
   2. Rarely involves tarsal bones or ankle
4. Findings: Rheumatoid Arthritis
   1. MTP joints commonly involved
   2. Bilateral ankles may be involved
5. Findings: Psoriatic Arthritis
   1. Foot commonly involved
   2. Sausage shaped toes may occur
   3. Classic psoriatic Plaque and Nail Pitting (60-80%)
   4. Ankle synovitis may be present
6. Findings: Reiter's Syndrome
   1. Foot commonly involved
   2. Sausage shaped toes may occur
7. Findings: Gout
   1. First MTP joint commonly involved (Podagra)
8. Findings: Pseudogout
   1. Occasionally involves Ankle Joint
9. Differential Diagnosis: Other common conditions of the foot
   1. Morton's Neuroma (commonly seen in runners and joggers)
      1. Paresthesias at second and third MTP joint web space
      2. Pain reproduced on palpation
   2. Plantar Fasciitis
      1. Heel Pain worse at first steps in the morning
   3. Achilles Tendonitis
      1. Also seen in patients with Spondyloarthropathy