Wart
A wart is a usually benign skin growth caused by infection with human papillomavirus (HPV). Its appearance and location vary by type.
Human papillomavirus: A large family of viruses that infect skin and mucous membranes; some types cause warts. Specific HPV types infect skin cells and trigger the growth that forms a wart.
Cutaneous human papillomavirus: An HPV type that infects skin and can cause cutaneous warts. These skin-infecting HPV types cause common, plantar, and several other wart forms.
Salicylic acid: A keratolytic medicine that softens and gradually removes thickened outer skin. Repeated application can remove wart tissue, especially on hands and feet.
Corn: A localized thickening of skin caused by repeated pressure or friction, often over a toe. A corn can resemble a plantar wart but arises from mechanical pressure, not HPV.
Contact transmission: The spread of an infectious agent through direct physical contact or contaminated surfaces. HPV can pass through contact with a wart or contaminated objects, especially when skin is damaged.
Keratinocyte: A skin cell that produces keratin, the tough protein forming much of the outer skin layer. HPV alters infected keratinocytes, producing the thickened surface of many warts.
Common wart: A rough, raised skin growth, often on the hands or fingers, commonly caused by HPV types 2 or 4. This familiar form shows the typical rough, raised appearance associated with warts.
Cryotherapy: A treatment that destroys tissue by freezing it, commonly with liquid nitrogen. Freezing is a standard clinic treatment for persistent cutaneous warts.
Callus: A broad area of thickened skin formed in response to repeated friction or pressure. Calluses can look like plantar warts but usually lack their disrupted skin markings.
Human papillomavirus vaccine: A vaccine that protects against selected HPV types linked to cancers and genital warts. Vaccination prevents infections by some wart-causing genital HPV types, though not most common skin-wart types.