Wart vs Skin Cancer: Telling Them Apart

Common wart (verruca vulgaris). Rough, raised, skin-coloured or grey-brown bump with a cauliflower-like surface. Typically 2-10mm. Most often on hands, fingers, knees, or feet. Painless except plantar warts on the sole, which can hurt with pressure.

Flat wart. Smaller (1-5mm), smoother, and flatter than common warts. Skin-coloured or slightly pink. Often in clusters on the face, hands, or shins.

Filliform wart. Long, thin, finger-like projection. Usually on the face, neck, or eyelids.

Plantar wart. On the sole of the foot. Often grows inward due to body weight pressure. Has small black dots on the surface (clotted capillaries) — a diagnostic feature.

Warts develop over weeks to months and are often multiple. They can resolve on their own (about two-thirds resolve within two years without treatment) or persist for years.

Squamous cell carcinoma (SCC). The most common 'wart mimic'. SCC can present as a rough, scaly, raised lesion, often on sun-exposed skin (face, ears, scalp, hands). Verrucous SCC specifically has a wart-like cauliflower surface and is most common on the soles of the feet, lips, and genitals. SCC is usually firmer than a typical wart and grows steadily.

Basal cell carcinoma (BCC). Less commonly mistaken for a wart, but the superficial subtype can appear as a scaly pink-red patch that resembles a flat wart. The pearly translucent quality usually distinguishes it on closer look.

Verrucous melanoma. A rare melanoma subtype with a wart-like surface. Pigment may be subtle or absent. Often misdiagnosed as a wart for months or years before biopsy.

Keratoacanthoma. A rapidly growing, dome-shaped lesion with a central crater filled with keratin. Looks like a sudden volcanic wart. Often classified as a low-grade SCC variant. Sometimes resolves on its own, but typically excised because it cannot be reliably distinguished from invasive SCC.

The consequence of mistaking these for warts is delay. Over-the-counter wart treatments do not cure cancer, and months of failed home treatment is months of growth.

Wart: develops over weeks. Once formed, often stable for months. May slowly resolve over a year or two. Can grow modestly but does not enlarge week-by-week.

SCC or verrucous melanoma: grows steadily over weeks to months. A 'wart' that is visibly larger from one month to the next is suspicious, especially in an adult over 50 or someone with significant sun damage history.

Keratoacanthoma is the exception — it grows rapidly over weeks. Any rapidly growing wart-like lesion needs a dermatology visit, not a pharmacy treatment.

Wart: usually does not bleed unless picked, scraped, or shaved. Black dots on a plantar wart are clotted capillaries within the wart, not bleeding from the surface.

SCC, BCC, and melanoma: can bleed spontaneously, scab, partially heal, then bleed again. The cycle of bleeding-scabbing-non-healing is one of the most reliable warning signs across all skin cancers. A 'wart' that bleeds at random or has been scabbing on and off for weeks needs evaluation.

Wart: responds, slowly, to standard treatments — salicylic acid, cryotherapy (freezing), or duct tape. Even resistant warts usually show some change after 4-8 weeks of treatment.

SCC mimicking a wart: does not respond to wart treatment. The lesion may scab from the chemical or freeze, but the underlying tumour persists and continues to grow underneath.

If a 'wart' has been treated for 8 weeks with no improvement, stop treating it as a wart. Book a dermatologist for biopsy.

Wart: more common in children and young adults. Often on hands, knees, or feet — areas of skin contact. New warts in older adults are less common (immune system handles HPV less efficiently with age, but new infections still happen).

SCC: more common after age 50, especially with significant sun exposure history, immunosuppression, or fair skin. A 'new wart' on the face, ear, lip, scalp, or back of hand of someone over 50 has a meaningfully higher chance of being SCC than a new wart on the hand of a 12-year-old.

The shift in pretest probability matters. Don't assume the same lesion has the same diagnosis at every age.

See a dermatologist (do not self-treat) if: the wart-like lesion is in someone over 50 with sun damage; it is on the face, lip, or ear; it is bleeding or non-healing; it has grown in the past month; OTC treatment has failed for 8 weeks; the patient is immunosuppressed; the lesion has any pigmentation that is unusual or growing.

Book within 2-4 weeks if: a longstanding wart in an adult has changed (size, surface, symptoms).

Book urgently (within 1-2 weeks) if: rapid growth; bleeding; non-healing crater; any wart-like lesion in someone with prior skin cancer.

Diagnosis is by shave or punch biopsy under local anaesthetic. SCC caught early is curable by simple excision in over 95% of cases. The reason to act is to keep the excision small.