Cutaneous warts

Overview

•All warts caused by HPV (double-stranded DNA virus) - type determines site and morphology

•HPV 6 and 11 - cause ~90% of genital warts; low-risk (non-oncogenic)

•HPV 16 and 18 - high-risk oncogenic types (cervical/anogenital carcinoma); do NOT typically cause visible warts

Presentation

•Common wart - rough, hyperkeratotic papule; disrupted skin markings; hands/fingers

•Plantar wart (verruca) - pain on walking; black dots on paring (thrombosed capillaries); side pressure more painful than direct

•Genital warts (condylomata) - soft, fleshy, cauliflower-like lesions on mucosal surfaces; OR keratinised on non-mucosal anogenital skin

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Biopsy is NOT routinely required - diagnosis is clinical. Reserve biopsy for atypical, non-healing, or rapidly changing lesions where malignancy (SCC, Bowen's disease) cannot be excluded.

Management

•Most warts in children resolve spontaneously within 2 years - treatment indicated if painful, cosmetically distressing, or requested

Genital wart management by lesion type
FeatureSoft/fleshy/mucosal wartsKeratinised/harder warts
First-linePodophyllum (podophyllotoxin 0.5% solution or 0.15% cream) - anti-mitotic; patient-applied; 3 days on / 4 days off, up to 4 cyclesCryotherapy - penetrates through keratin better; applied in clinic
Second-lineImiquimod 5% cream - immune response modifierImiquimod 5% cream
ContraindicationPodophyllum contraindicated in pregnancy-

Feature	Soft/fleshy/mucosal warts	Keratinised/harder warts
First-line	Podophyllum (podophyllotoxin 0.5% solution or 0.15% cream) - anti-mitotic; patient-applied; 3 days on / 4 days off, up to 4 cycles	Cryotherapy - penetrates through keratin better; applied in clinic
Second-line	Imiquimod 5% cream - immune response modifier	Imiquimod 5% cream
Contraindication	Podophyllum contraindicated in pregnancy	-

•Non-genital (cutaneous) warts - first-line: topical salicylic acid (12-26% hands; up to 50% plantar) - applied daily after paring and soaking

•Non-genital - second-line: cryotherapy (liquid nitrogen) - 10-30 second freeze-thaw cycles every 2-3 weeks; or combination salicylic acid + cryotherapy

•Third-line / recalcitrant: imiquimod 5% cream (off-label); surgical options (curettage, excision, laser) - dermatology referral

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For genital warts: soft/fleshy mucosal lesions → podophyllum first (anti-mitotic works on rapidly dividing cells). Keratinised/harder lesions → cryotherapy first (podophyllum penetrates poorly through keratin). Imiquimod is second-line in both.

•Surgical excision / electrocautery - reserved for large, bulky, or treatment-resistant lesions; requires anaesthesia; specialist setting

•Urethroscopy - only if urinary symptoms suggesting urethral warts