Synopsis
Classify flexible and fixed lesser-toe deformity, treat callus as evidence of pressure rather than a skin diagnosis alone, identify neuropathy and ischaemia, and combine footwear, podiatry, orthoses and surgery without creating ulcer risk.
- Classify the deformity precisely: hammer toe mainly flexes at the proximal interphalangeal joint, mallet toe at the distal joint, and claw toe combines metatarsophalangeal hyperextension with both interphalangeal joints flexed.
- Test flexibility with the ankle and metatarsophalangeal joint positioned to relax tendons; a reducible deformity can respond to footwear, padding, splinting and exercise better than a fixed joint.
- Callus and corns are pressure maps: dorsal corns indicate shoe contact, tip lesions indicate end pressure, interdigital soft corns indicate crowding and plantar callus indicates metatarsal loading.
- First-line assessment includes standing alignment, joint stability, footwear, skin inspection, monofilament protective sensation, pulses and capillary refill in both feet.
- First-line management is a wide and deep toe box, sufficient shoe length, low heel, pressure-specific padding, podiatry debridement and correction of the underlying load where possible.
- Do not advise self-cutting or salicylic-acid corn plasters in diabetes, neuropathy, ischaemia or fragile skin; a professional should inspect beneath haemorrhagic callus.
- Use weight-bearing radiographs for fixed, progressive or surgical deformity; perform neurological, diabetes and vascular testing when examination suggests systemic drivers.
- Refer painful fixed deformity, recurrent ulceration or failed shoe accommodation for procedure selection that corrects metatarsophalangeal instability and tendon imbalance, not the corn alone.
Key red flags
Dark haemorrhage beneath callus, fluctuance or a skin break can conceal a neuropathic ulcer and requires prompt debridement and depth assessment by a trained foot service.
Spreading redness, warmth, purulence, lymphangitis, fever or systemic compromise requires urgent infection grading, antibiotics and source-control assessment.
Rest pain, coolness, pallor, delayed refill, tissue loss or absent pulses requires vascular review before debridement, padding or elective correction.
Rapidly progressive clawing, asymmetric weakness, cavus change or widespread sensory loss requires neurological investigation rather than shoe treatment alone.
A hot swollen neuropathic foot with changing shape requires immediate non-weight-bearing Charcot assessment.
Investigation priorities
Classify deformity, pressure site, reducibility, metatarsophalangeal stability and footwear conflict.
Identify neuropathy and arterial disease that convert callus into ulcer and treatment risk.
Management branches
A corn, callus or lesser-toe deformity presents without active ulcer, infection or ischaemia.
- Classify hammer, claw, mallet or crossover pattern, test reducibility and examine metatarsophalangeal stability.
- Inspect every pressure surface and footwear and assess monofilament sensation, pulses, refill and arch or hallux contribution.
- Provide adequate shoe length, width and depth and select a pad or spacer that unloads rather than transfers pressure.
- Arrange podiatry debridement for symptomatic thick callus and combine it with flexible-toe and calf-foot rehabilitation.