Differential Diagnosis for Plantar Fasciitis

When considering the diagnosis and management of plantar fasciitis, it's crucial to differentiate it from other potential causes of heel pain. Here's a structured approach to the differential diagnosis:

• Single Most Likely Diagnosis

  • Plantar fasciitis: This is the most common cause of heel pain, characterized by inflammation of the plantar fascia, a band of tissue that supports the arch of the foot. The typical presentation includes pain on the underside of the heel that worsens with the first steps after awakening or after periods of rest.

• Other Likely Diagnoses

  • Achilles tendinitis: Inflammation of the Achilles tendon, which connects the calf muscles to the heel bone, can cause pain in the back of the heel.
  • Calcaneal stress fracture: A small crack in the heel bone can cause pain that is often confused with plantar fasciitis.
  • Fat pad atrophy: Thinning of the fat pad under the heel can lead to pain due to decreased cushioning.
  • Heel spur: A bony growth on the underside of the heel bone, which can cause pain when it irritates the plantar fascia.

• Do Not Miss Diagnoses

  • Infection (e.g., osteomyelitis, septic arthritis): Although rare, infections in the foot or ankle can be serious and require prompt antibiotic treatment.
  • Tumor: Both benign and malignant tumors can occur in the foot and may present with pain.
  • Peripheral artery disease: Reduced blood flow to the feet can cause pain, especially during activity, and is a significant concern due to its implications for overall cardiovascular health.
  • Nerve entrapment (e.g., tarsal tunnel syndrome): Compression of nerves in the foot can cause pain, numbness, and tingling.

• Rare Diagnoses

  • Paget's disease of bone: A condition that affects bone remodeling, leading to weakened bones and potential for deformities.
  • Rheumatologic diseases (e.g., rheumatoid arthritis, ankylosing spondylitis): These conditions can cause heel pain as part of a broader spectrum of symptoms affecting the musculoskeletal system.
  • Gout or pseudogout: Deposition of urate crystals or calcium pyrophosphate dihydrate crystals, respectively, can cause acute, severe pain in the foot, including the heel.

Each of these diagnoses has distinct clinical features and may require specific diagnostic tests for confirmation. A thorough history, physical examination, and sometimes imaging studies are essential for accurately diagnosing the cause of heel pain and guiding appropriate treatment.