What is the typical presentation of a cutaneous wart and what are the first‑line treatment options?

Cutaneous Warts: Clinical Presentation and First-Line Treatment

Typical Clinical Presentation

Cutaneous warts are hyperkeratotic papulonodules caused by HPV infection that disrupt normal skin lines and reveal pinpoint bleeding when pared—this pathognomonic finding distinguishes them from corns (translucent core) and calluses (homogeneous keratin without bleeding). 1

Key Diagnostic Features

• Common warts appear as rough, hyperkeratotic papules with absent or disrupted dermatoglyphics (skin lines) across the lesion surface. 2

• The definitive diagnostic test involves soaking the lesion in warm water for 5-10 minutes, then gently paring with a scalpel or emery board to reveal pinpoint bleeding from exposed capillary loops—this is pathognomonic for warts. 1, 3

• HPV types 1,2,4,27, and 57 cause common warts, with HPV-2 being most prevalent; the infection is most common in the second decade of life, affecting over 40% of children. 2, 4

• Warts can occur anywhere on the body but commonly affect hands, feet (plantar warts/verrucae), and face (often flat warts). 1

Critical Differential Diagnoses to Exclude

• Squamous cell carcinoma must be excluded in any non-healing, treatment-resistant hyperkeratotic lesion, especially in elderly or immunosuppressed patients—red flags include ulceration, bleeding, rapid growth, and treatment failure, all mandating biopsy. 1

• Actinic keratoses present as erythematous, rough, scaling patches on chronically sun-exposed skin (dorsal hands, face) in middle-aged to elderly individuals and are premalignant. 1, 2

• Seborrhoeic keratoses appear as "stuck-on," waxy lesions with preserved skin lines (unlike warts) and variable pigmentation in older adults. 1, 2

First-Line Treatment Options

Topical salicylic acid 15-26% applied daily for 3-4 months after paring is the first-line treatment with the strongest evidence (Level 1+, Grade A), offering the best balance of efficacy and safety. 3

Salicylic Acid Protocol (First-Line)

• Soak the wart in warm water for 5-10 minutes, then pare down the thickened white keratin layer using a disposable emery board, pumice stone, or callus file—stop if pinpoint bleeding appears. 3

• Apply salicylic acid 15-26% daily to the pared surface, ideally with occlusion using a bandage or tape to enhance penetration. 3

• Continue treatment for a full 3-4 months before declaring failure; patient compliance is crucial but often poor due to surrounding skin irritation. 3

• Discard the paring tool after each use or dedicate it solely to the wart to prevent spreading infection. 3

• For facial warts, use only weak salicylic acid creams (2-10%) without occlusion and exercise extreme caution, as destructive therapies carry high scarring risk. 1

Cryotherapy (Second-Line)

• If salicylic acid fails after 3 months, switch to cryotherapy with liquid nitrogen applied every 2-4 weeks, freezing for 15-30 seconds per treatment, continuing for at least 3 months or up to six treatments. 3

• Cryotherapy is more effective than salicylic acid alone but carries higher risk of pain, blistering, and scarring. 5

• Combination treatment with salicylic acid and cryotherapy yields significantly higher remission rates than either modality alone and may reduce side effects. 6, 5

Expectant Management (Acceptable Alternative)

• Watchful waiting is entirely acceptable for immunocompetent patients with asymptomatic warts, as approximately 50% resolve spontaneously within one year in children and two-thirds by two years; in adults, warts may persist 5-10 years without treatment. 1, 3

• Active treatment is warranted when warts cause significant pain, functional impairment, cosmetic concern, or embarrassment. 1

Critical Pitfalls to Avoid

• Never assume all hyperkeratotic lesions are benign warts—maintain high suspicion for squamous cell carcinoma in elderly, sun-damaged, or immunosuppressed patients, and biopsy any lesion that fails standard therapy, is pruritic, pigmented, enlarging, or atypical. 1, 2

• Do not stop treatment prematurely; salicylic acid requires 3-4 months and cryotherapy needs at least 3 months or six treatments before declaring failure. 3

• Avoid aggressive destructive therapy on facial warts without extreme caution, as permanent scarring can outweigh the original lesion's cosmetic impact. 1

• Recognize that wart treatments do not eradicate HPV infection; recurrence occurs in at least 25% of cases within three months with all modalities, as HPV persists in surrounding normal skin and can remain infectious in the environment for months to years. 1, 2

Special Populations Requiring Modified Approach

• Immunosuppressed patients (organ transplant recipients, HIV-positive individuals, lymphoma patients) develop larger, more extensive, treatment-resistant warts with elevated risk of HPV-associated squamous cell carcinoma—maintain a lower threshold for biopsy of atypical lesions. 1, 2

• Severe or prolonged warts may signal underlying immunosuppression (lymphoma, CD4 lymphocytopenia, HIV) and warrant immune evaluation. 1