Key facts
- Viral wart
- An HPV-driven epidermal growth; contagious by contact and self-spread through scratching or shaving
- Seborrhoeic keratosis
- A benign, non-viral proliferation of surface keratinocytes — the 'age wart' or 'stucco-on' lesion of maturity
- HPV
- Human papillomavirus — over 200 types; common warts involve types that infect skin keratinocytes
- Distribution
- Viral warts favour hands, feet and shaving areas; seborrhoeic keratoses favour face, scalp and trunk
- Black dots
- Thrombosed capillaries in a viral wart's surface — a distinguishing feature under magnification
- Removal methods
- Cryotherapy, radiofrequency/laser ablation, curettage — matched to lesion type, site and number
- Contagiousness
- Viral warts: yes, including self-spread. Seborrhoeic keratoses: never
Two lesions, one lay name
A viral wart is an infection: HPV persuades surface skin cells to over-multiply into a rough, disruptive papule, and the virus in that papule can seed new warts — on you, and occasionally on others. A seborrhoeic keratosis is not an infection at all: it is a benign proliferation that skin produces with the decades, sitting on the surface with a characteristic waxy, 'stuck-on' look, as though it could be peeled off. One spreads and recruits; the other simply multiplies with age on its own schedule. Everything downstream — urgency, method, prevention — follows from which one you have.
“One of these lesions is an infection. The other is maturity. Treating them identically is how both get treated badly.”
Dr Sin YongOn viral warts versus seborrhoeic keratoses
How to tell them apart
Viral warts are rough, firm, and interrupt the skin's fingerprint lines; under magnification they show pinpoint black dots — thrombosed capillaries — and they favour hands, fingers, soles and shaving zones. Seborrhoeic keratoses look painted on: waxy or warty plaques in tan, brown or near-black, with a matte, keratotic surface, scattered across the temples, cheeks, trunk and hairline in patterns that often echo a parent's. Age helps too — a new crop of lesions in the fifties is far more often seborrhoeic keratoses. But dark or changing lesions matter: a seborrhoeic keratosis can occasionally mimic a melanoma and vice versa, which is why the confident diagnosis belongs in a clinic, not a mirror.
Removing viral warts properly
Because a viral wart is infected tissue, removal aims to destroy it fully while the immune system deals with the virus. Options include cryotherapy in cycles, ablation by radiofrequency or laser, and curettage for suitable lesions — chosen by site, depth and number. Plantar warts on weight-bearing soles are the stubborn ones, often needing repeated cycles regardless of method, and honesty matters here: recurrence after apparently complete treatment is common with warts everywhere in the world, because virus can persist in adjacent clinically normal skin. Persistence wins; single-session promises do not.
Removing age warts
Seborrhoeic keratoses are the more grateful lesion: superficial by nature, they ablate or curette off cleanly under local anaesthesia, typically in one sitting, with modest aftercare and no virus to recur. Multiple facial lesions are commonly cleared in a single session. The main considerations are cosmetic — controlled depth to avoid marks, and sun protection during healing, since post-inflammatory pigmentation is the principal risk in our climate and skin types. New keratoses will appear elsewhere over the years because the tendency is constitutional; that is maturity, not relapse.
When a 'wart' deserves a doctor promptly
Any lesion that is bleeding without provocation, growing quickly, ulcerating, intensely dark or irregular, or simply behaving unlike its neighbours deserves examination rather than removal-by-assumption. The point of assessment before ablation is the same as with moles: destroyed tissue answers no questions. It takes minutes to be sure, and the rare occasions when 'just a wart' is something else are exactly the occasions the assessment exists for.
