Wart (HPV - human papillomavirus)
Clinical types of warts
| Type | VPH | Location | Aspect |
|---|---|---|---|
| Common wart (verruca vulgaris) | HPV 1 + 2 + 4 | Arms + hands + knees + elbows + periungual area | Firm keratotic papule or nodule + rough «cauliflower-like» surface + flesh-colored or grayish + black puncta (thrombosed capillaries = characteristic black dots) + disappearance of dermatoglyphs |
| Plantar wart (myrmecium) | HPV 1 | Sole of the foot + support zones (heel + metatarsal heads) | Endophytic lesion (sinks into the dermis under pressure) + surrounded by a keratotic ring + very painful to the touch + characteristic black puncta + can be mistaken for a callus (corn) — but a callus does not have black puncta |
| Mosaic warts | HPV 2 + 27 | Sole of the foot | Plaque of multiple small, coalescing warts + superficial surface + less endophytic + less painful than a myrmecium + difficult to treat |
| Flat wart (verruca plana) | HPV 3 + 10 | Face + forehead + backs of hands + limbs | Flat papules + slightly raised + flesh-colored or slightly pigmented + multiple + often arranged in lines (Koebnerization) + sometimes itchy |
| Filiform warts | HPV 1 + 2 + 4 | Face (lips + nose + eyelids) | Threadlike projections + fine + on a stalk + «horn» or filament appearance + very characteristic |
| Genital warts (condylomata acuminata) | HPV 6 + 11 (low risk) | Genital, anal, and perineal region | Papules + «cockscomb» verrucosities + pink or grayish + multiple + STD — see condyloma fact sheet |
Treatment
- Therapeutic abstention (a valid option in children): 65 % de régression spontanée en 2 ans + 80 % en 3–4 ans → chez l'enfant avec verrues peu gênantes et non douloureuses + l'attente active est une option raisonnable + particulièrement si le traitement serait douloureux ou anxiogène
- Salicylic acid (first-line treatment — strongest data) Solution or gel at 12–40 % (Duofilm® + Compound W® + Verrugon®) + daily application after soaking the area in hot water for 5 min + gentle sanding with a file or pumice stone + product application + occlusion (adhesive bandage) → keratolytic action → progressive wart destruction + 70–75 % healing rate after 12 weeks of regular treatment + well-tolerated + inexpensive + first-line treatment for all common and plantar warts
- Liquid nitrogen cryotherapy (−196 °C): Liquid nitrogen application by cryospray or swab to wart → freeze-thaw cycles (2 cycles of 20–30 seconds per session) → destruction of infected keratinocytes by intracellular ice formation + inflammation then necrosis + healing rate 60–70% % after 3–4 sessions at 2–3 week intervals + painful + can cause blisters + scarring + dyschromia + treatment of choice in medical consultation for adult warts refractory to salicylic acid
- Salicylic acid + cryotherapy combination: superior to each treatment alone according to meta-analyses → use salicylic acid continuously between cryotherapy sessions
- Imiquimod cream 5% % (Aldara®): Topical immunomodulator → Stimulation of local innate immunity + T-cell activation → Modest efficacy on common warts + But used for genital warts (FDA approval) + and flat warts (off-label)
- Trichloroacetic acid (TCA 80-90 %): Caustic agent -> chemical destruction of tissue -> used by the doctor for condylomas + and sometimes refractory plantar warts + applied in a controlled manner
- Cantharidin (Canthacur®): Vesicant extract from the insect Lytta vesicatoria → Doctor's application + blister formation under wart → peeling and destruction + no scarring + particularly useful for children (painless application) + not approved in some countries but used in common practice in Canada
- CO₂ Laser + electrodesiccation For stubborn, numerous, periungual warts, or in immunocompromised individuals → under local anesthesia + risk of scarring
- Diphenylcyclopropenone (DPCP) Immunotherapy: Contact immunotherapy → skin sensitization → localized allergic reaction → immunological destruction of warts + effective for multiple refractory warts + used in specialized dermatology
HPV Vaccination - Primary Prevention
- Gardasil 9® vaccine (nonavalent — HPV 6 + 11 + 16 + 18 + 31 + 33 + 45 + 52 + 58): Protects against genital warts (HPV 6 + 11) + cervical cancer + anal cancer + oropharyngeal cancers + vulvar + vaginal + penile cancers (HPV 16 + 18 + 5 other oncogenic genotypes)
- Quebec Vaccination Program: 2 doses (0 + 6–12 months) if initiated before 14–15 years of age + 3 doses (0 + 2 + 6 months) if initiated after 15 years of age + vaccine offered free of charge in 4th grade (girls + boys) in Quebec schools + catch-up until 26 years of age + vaccination recommended up to 45 years of age for certain at-risk populations
- Efficiency : 98–100 % prevention of genital warts and precancerous cervical lesions due to covered genotypes + maximum efficacy if vaccinated before the start of sexual activity (before any HPV exposure)
- Important note: The HPV vaccine protects against genital warts and HPV-related cancers, but it does NOT protect against common warts and plantar warts (caused by different genotypes – HPV 1, 2, and 4 – not covered by the vaccine).
Consult a doctor if a wart is painful, interferes with walking, or does not respond to salicylic acid treatment after 3 months. Also consult a doctor if multiple, recurrent warts appear in an adult (suspect immunodeficiency), or if a wart-like lesion shows rapid growth, bleeding, or ulceration (rule out verrucous squamous cell carcinoma). For cryotherapy or cantharidin treatment and prescription medication for recalcitrant warts, Clinique Omicron offers medical consultations at its service points in Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's specialist nurse practitioners (SNPs) diagnose warts and differentiate them from corns, calluses, and other keratoses. They prescribe and administer treatments (salicylic acid + cryotherapy + cantharidin based on type, location, and age), evaluate recurrent multiple warts in adults to rule out immunodeficiency, refer to dermatology for recalcitrant warts requiring advanced treatments, and administer the Gardasil 9 vaccine for the prevention of oncogenic HPV infections. Consultations are available at several service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
Le contenu de cette page est fourni à titre informatif uniquement et ne remplace pas l'avis d'un médecin ou d'un dermatologue. Chez l'enfant immunocompétent, 65 % des verrues régressent spontanément en 2 ans — l'abstention thérapeutique est une option valide pour les verrues peu gênantes. Le vaccin VPH (Gardasil 9) ne protège pas contre les verrues cutanées vulgaires et plantaires — ces dernières sont causées par des génotypes différents non couverts par le vaccin.
Omicron Clinic
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