How can I tell whether I have a wart or a corn?
Short answer: Warts often interrupt normal skin lines and contain pinpoint capillaries; corns usually preserve skin lines and form over pressure. These clues help, but examination after careful paring is more reliable than appearance alone.
A plantar wart may hurt when squeezed from side to side, whereas a corn often hurts most with direct pressure. Neither test is perfect. Thick callus can hide the surface pattern, and a painful wart may also develop a pressure-related callus over it.
Other mimics include porokeratosis, foreign-body reaction, epidermal cyst, callus over a bony prominence and, rarely, skin cancer. Pigmentation, ulceration, rapid growth, persistent bleeding, marked asymmetry or failure to behave as expected warrants diagnostic reconsideration.
Dermoscopy can improve visual assessment. Biopsy may be required for an atypical lesion, an uncertain diagnosis or a treatment-resistant growth—especially in an older or immunosuppressed patient. Destructive treatment should not continue indefinitely without confidence in the diagnosis.
When should I seek an assessment?
Consider assessment when the diagnosis is uncertain, the lesion is painful or changing, warts are spreading, self-care is unsafe, or reasonable treatment has failed. Chronic lesions should be re-examined before another destructive course is started.