Foot Pain / Discomfort

Question 1

Differential Diagnoses of Foot Pain

Answer 1

1. Gout
2. Alcoholic Neuropathy

Probability diagnosis 
Acute or chronic foot strain 
Sprained ankle
Osteoarthritis (esp. great toe – hallux rigidus)
Plantar fasciitis
Achilles tendonopathy
Tibialis posterior tendonopathy 
Wart, corn or callus
Ingrowing toenail/paronychia

Serious disorders not to be missed
Vascular insufficiency:
•small vessel disease

Neoplasia/cancer:
•osteoid osteoma
•osteosarcoma
•synovial sarcoma
•acral lentiginous melanoma

Infection (rare):
•septic arthritis
•actinomycosis
•osteomyelitis

Rheumatoid arthritis
Peripheral neuropathy
Complex regional pain syndromes
Ruptured Achilles’ tendon 
Ruptured tibialis posterior tendon 

Pitfalls (often missed)
Foreign body (especially children)
Gout

Nerve syndromes:
•Morton neuroma
•tarsal tunnel syndrome
•deep peroneal nerve
Chilblains
Stress fracture (e.g. navicular)
Erythema nodosum

Rarities:
•spondyloarthropathies
•osteochondritis: 
navicular (Köhler), 
metatarsal head (Freiberg), 
calcaneum (Sever)

Glomus tumour (under nail)
Paget disease

Masquerades checklist
Diabetes
Drugs
Spinal dysfunction

Is the patient trying to tell me something?
A non-organic cause warrants consideration with any painful condition.

Question 2

Foot Pain - Key History

Answer 2

Key history

Ask about the quality of the pain, its distribution, mode of onset, periodicity, relationship to weight-bearing and associated features such as swelling or colour change. Enquire about pain in other joints including sacroiliac joints.

Question 3

Foot Pain - Key Examination

Answer 3

Key examination

• Follow the inspection, palpation, movement and test function approach
• Test active and passive movements of the ankle (talar) joint, hindfoot (subtalar) joint and mid-foot (midtarsal) joint
• Check the peripheral circulation and perform a neurological examination including sensation, motor strength and reflexes

Question 4

Foot Pain - Key investigations

Answer 4

Key investigations

Consider:
•FBE
•ESR/CRP
•rheumatoid arthritis tests
•blood glucose
•uric acid
•nerve conduction studies and imaging (e.g. plain X-ray—compare both sides)
•ultrasound 
•MRI
•radionuclide scans.

Question 5

Foot Pain - Diagnostic Tips

Answer 5

Diagnostic tips

• Good quality plain X-rays are important if there is doubt about the diagnosis of a painful foot.
• Foot strain is probably the commonest cause of podalgia.
• All the distal joints of the foot may be involved in arthritic disorders.