Human Papillomavirus Infections
Human papillomavirus (HPV) infection is one of the most common skin and mucosal infections in dermatology and reproductive medicine. HPV is a non-enveloped, double-stranded DNA virus of the family Papillomaviridae, with more than 200 genotypes. It is strongly epitheliotropic, multiplying only in differentiating keratinocytes of the stratified squamous epithelium of the skin and mucous membranes. Its way in is through micro-abrasions in the epidermal barrier, which give the virus access to stem cells in the basal layer.
Based on their potential to cause cancer, HPV types fall into two main groups. Low-risk HPV mainly causes benign growths on the skin (common, flat and plantar warts) or genital mucosa (genital warts). High-risk HPV can integrate its DNA into the host genome and overproduce the E6 and E7 oncoproteins, which inactivate the tumor suppressor proteins p53 and pRb. This leads to epithelial dysplasia and carcinoma (cancers of the cervix, anus, penis and oropharynx).
At Haute-Derma, managing HPV skin lesions goes beyond removing the rough surface growth. We take a comprehensive approach: dermoscopy-guided assessment, real-time PCR HPV genotyping, Superpulse CO2 laser to precisely vaporize infected tissue, long-pulse 1064 nm Nd:YAG laser to shut down feeding vessels, and topical immune-stimulating treatments to minimize recurrence and preserve the skin's appearance as much as possible.
How HPV Causes Disease and Transforms Cells
HPV Genotypes and Their Target Sites
- Cutaneous HPV types:
- HPV 1: The leading cause of deep plantar warts (myrmecia).
- HPV 2, 4, 7, 27, 57: Common warts (verruca vulgaris).
- HPV 3, 10, 28, 49: Flat warts (verruca plana).
- Mucosal and anogenital HPV types:
- Low risk (HPV 6, 11): Cause more than 90% of genital warts (condyloma acuminata) and laryngeal papillomas.
- High risk (HPV 16, 18, 31, 33, 45, 52, 58): The main causes of intraepithelial neoplasia (CIN, VIN, PIN) and of cervical and anogenital cancers.
The Role of the E6/E7 Oncoproteins and Koilocytosis
- E6 oncoprotein: Binds p53 (the cell cycle gatekeeper) and marks it for destruction by the proteasome, so damaged cells can no longer trigger programmed cell death (apoptosis).
- E7 oncoprotein: Binds and inactivates pRb (the retinoblastoma protein), releasing the transcription factor E2F and pushing cells from G1 into S phase without normal checks.
- Koilocytosis: Explosive viral replication in the upper epidermis produces the classic histologic finding, the koilocyte: a keratinocyte with a dark, shrunken, misshapen nucleus surrounded by a clear space in the cytoplasm (perinuclear halo).
Our Diagnostic Workup at Haute-Derma
Digital Dermoscopy:
- Common and plantar warts: Dermoscopy shows a papillomatous surface with central red or gray-black dots (thrombosed capillaries in the dermal papillae), surrounded by a whitish-gray keratin halo. Interruption of the normal skin lines over the lesion is the key sign that distinguishes a wart from a callus.
- Genital warts: Finger-like projections, each with a central dotted or looped blood vessel.
Molecular Testing (Real-Time PCR HPV Genotyping): Used for anogenital warts and mucosal lesions. DNA extraction identifies high-risk types (HPV 16, 18, 31, 33 and others) so we can estimate prognosis and plan regular cancer screening.
Biopsy (for Resistant Lesions or Suspected Malignancy): Indicated when a lesion ulcerates for a long time, grows quickly or does not respond to treatment. Typical findings are hyperkeratosis, acanthosis, papillomatosis and koilocytes in the upper epidermis.
Management and Cosmetically Focused Treatment at Haute-Derma
Chemical and Topical Treatments
- Combined keratolytics: Salicylic acid 16.7% + lactic acid 16.7% solution (Duofilm) applied daily after soaking in warm water and filing down the hard skin. Effective for plantar and hand warts.
- Prescription topical agents:
- Podophyllotoxin 0.5% or sinecatechins 10%: applied to treat mild genital warts.
- Trichloroacetic acid (TCA 80%–90%): Applied precisely to the wart, denaturing proteins and destroying virus-infected cells.
- Topical immune stimulants:
- Imiquimod 5%: Applied three evenings a week. It activates the TLR-7 receptor so the skin makes its own interferon-alpha and TNF-alpha to fight HPV, and is especially useful for reducing recurrence of genital warts and flat warts on the face.
Advanced Procedures at Haute-Derma
- Superpulse CO2 laser (precise vaporization):
- The 10,600 nm wavelength in ultra-short Superpulse mode vaporizes HPV-infected cells layer by layer while limiting heat spread to the surrounding healthy tissue. It is a first-line option for large common warts, periungual warts and genital warts.
- Long-pulse 1064 nm Nd:YAG laser (shutting down feeding vessels):
- The 1064 nm wavelength penetrates deeply and targets hemoglobin in the capillaries feeding the wart, coagulating them. Without a blood supply, the wart regresses and falls off on its own without leaving an open wound, keeping the risk of infection low.
- Liquid nitrogen cryotherapy:
- Liquid nitrogen (−196°C) is sprayed on the wart in freeze-thaw cycles to destroy the virus-infected epidermal cells.
Skin Recovery and Preventing Recurrence
- Aftercare: A moisturizer with vitamin B5, zinc oxide and madecassoside helps the skin repair quickly and limits post-inflammatory hyperpigmentation (PIH).
- Vaccine counseling: We recommend the Gardasil 9 vaccine (covering 9 HPV types: 6, 11, 16, 18, 31, 33, 45, 52, 58) to build active immune protection.
