Wart Common (ICD-10: B07) ⚠️

Common Wart (Verruca Vulgaris): Benign Viral Skin Neoplasm

Overview

Common warts, or verruca vulgaris, are benign skin growths caused by infection with the human papillomavirus (HPV), particularly low-risk strains. These warts appear as raised, rough-surfaced lesions that most commonly develop on the hands and fingers. Though they are non-cancerous and generally painless, their visible appearance, tendency to spread, and resistance to treatment—especially in adults—make them a common dermatological concern.

Viral warts are especially prevalent among children and adolescents, affecting nearly 10% of this population. While spontaneous regression is possible (occurring in up to 40% of adolescents), the likelihood of spontaneous resolution decreases with age. Warts are typically multiples, may recur, and frequently prove resistant to conservative therapy—especially in immunocompromised individuals.

Predisposing Factors and Transmission

Warts are caused by specific strains of HPV, which infect the skin through micro-abrasions or damaged epithelial surfaces. While HPV is extremely widespread, not everyone who comes into contact with the virus will develop warts—suggesting a significant role of host immune factors.

Common risk factors for developing verruca vulgaris include:

• Exposure to HPV through a break in the skin: The virus needs a route in. Cuts, grazes, hangnails, bitten nails and skin softened by moisture all provide one;
• Direct contact with another person’s wart, or indirect contact with a surface or object they have used;
• Autoinoculation: Touching, scratching, picking or shaving a wart transfers virus to other sites on one’s own skin;
• Immunosuppression: HIV infection, cancer treatment, or immunosuppressive drugs — including after organ transplantation — allow warts to develop more readily, become more numerous and persist much longer;
• Existing chronic skin diseases: Such as eczema, where a damaged barrier creates portals of viral entry.

HPV transmission occurs through direct skin contact with infected tissue or indirectly via fomites—contaminated surfaces, personal items, or tools. Autoinoculation is also possible when individuals touch or scratch one lesion and spread the virus to adjacent skin.

Diagnosis of Common Warts

Diagnosis is typically clinical and based on the lesion’s characteristic appearance. In straightforward cases, no laboratory testing is required. However, diagnostic tools can assist in atypical or persistent cases, especially if malignancy is suspected.

Diagnostic techniques include:

• Visual examination: Identification of classic morphological features such as rough surface, papillary texture, and interruption of normal skin lines;
• Dermatoscopy: Enhances visualization of key internal vascular and structural features of the wart (see below);
• HPV DNA typing: Not part of the routine assessment of a common wart. Identifying the viral type does not change how the wart is treated;
• Biopsy: Indicated in lesions that are rapidly growing, atypical in appearance, or unresponsive to treatment. Histopathology reveals hyperkeratosis, papillomatosis, and koilocytosis.

Clinical Presentation and Symptoms

Common warts appear as small, skin-colored or slightly grayish papules with a rough, irregular surface. Their papillomatous architecture resembles miniature cauliflower-like growths. They may be solitary or grouped, and in some cases, lesions coalesce to form conglomerates.

Key clinical features include:

• Location: Predominantly found on the hands, fingers, and periungual areas; occasionally on the face, knees, or body;
• Size: Typically 2–5 mm in diameter and 1–3 mm in elevation; larger or confluent lesions may exceed 1 cm;
• Surface texture: Keratinized, dry, and rough to touch with tiny projections;
• Color: Usually flesh-toned or pale gray; keratin buildup may give a darker appearance;
• Edges: Clearly demarcated with a “cliff-like” corolla from adjacent healthy skin;
• Hair growth: Absent on the wart surface, but surrounding skin may have normal follicles;
• Symptoms: Typically asymptomatic, but pressure may cause tingling or discomfort—especially in palmar or plantar warts.

Dermatoscopic Description

Dermatoscopy offers non-invasive visualization of key features that aid in confirming the diagnosis of viral warts. Hallmark dermatoscopic patterns include:

• “Frogspawn” appearance: Densely packed, keratinized papillae with a central red dot (feeding capillary);
• Thrombosed capillaries: Seen as red, brown or black dots, typically sitting within the papilliform structures; these clotted vessels are the most useful single feature;
• A pale rim of keratin may mark the boundary with healthy skin. This is a supporting observation rather than a defining hallmark, and its absence does not argue against the diagnosis;
• Lack of pigment network: Differentiates viral warts from pigmented nevi or melanomas.

These dermatoscopic features are crucial in distinguishing verruca vulgaris from other skin lesions such as seborrheic keratoses, melanocytic nevi, and malignancies.

Differential Diagnosis

Although the diagnosis of common warts is often straightforward, a number of other dermatological conditions can present with similar morphology. Accurate differentiation is important, particularly for persistent or atypical lesions. The differential diagnosis includes:

• Papillomatous nevus: Typically more pigmented, with longer-term presence and possible congenital history;
• Nevus sebaceous: Yellowish, plaque-like lesions usually seen on the scalp or face from early childhood;
• Halo nevus: Pigmented mole surrounded by a depigmented halo—no keratinization;
• Dermatofibroma: Firm nodules with a “dimple sign” when pinched;
• Flat wart (verruca plana): Smoother, smaller, and more often seen in young people on the face or extremities;
• Plantar wart: Located on the soles of the feet, often painful and embedded in skin creases;
• Molluscum contagiosum: Dome-shaped lesions with central umbilication and soft, white core;
• Basal cell carcinoma (nodular form): Pearly, slow-growing nodule, may ulcerate or bleed;
• Amelanotic melanoma: Rare, rapidly evolving lesion that lacks pigmentation—biopsy required for confirmation.

Risks: Clinical Significance of Warts

From an oncological standpoint, common warts are considered benign and do not pose a significant risk of malignancy. However, vigilance is required in lesions that exhibit suspicious features, such as:

• Sudden and rapid growth;
• Increased firmness or change in consistency;
• Ulceration, bleeding, or spontaneous pain;
• Color changes or irregular borders.

Besides cosmetic discomfort, warts may cause functional and hygiene issues:

• Trauma: Warts on hands are prone to repeated irritation and injury, leading to bleeding and risk of secondary infection;
• Autoinoculation: Scratching or damaging one wart can lead to multiple new lesions on adjacent skin;
• HPV carriage: Even asymptomatic carriers can transmit low-risk HPV to others or to other parts of their body.

Tactics: Clinical Strategy and Monitoring

Common warts are harmless, and many clear by themselves — so leaving an unchanged, symptom-free wart alone is a legitimate choice rather than neglect. No routine schedule of checks is needed. Dermatologic evaluation is advised when:

• There is mechanical injury, friction from clothing or jewelry;
• The wart changes in appearance or sensation (e.g., becomes painful, bleeds);
• There is significant cosmetic or psychological impact;
• The patient belongs to a high-risk group (e.g., immunocompromised, patients with extensive or recurrent warts);
• The wart is located in high-friction or occupationally sensitive areas.

Photographic documentation and skin-lesion mapping are tools for following people at risk of skin cancer; they are not needed for uncomplicated common warts.

Treatment of Common Warts

Treatment is worth considering when warts are painful, awkwardly placed, repeatedly traumatised, spreading, or simply unwanted. It is equally reasonable to do nothing, since a substantial proportion of warts disappear without any intervention — most quickly in children. Standard options are:

• Topical salicylic acid: The mainstay of self-applied treatment. It works by thinning the keratin over weeks of daily use, ideally after soaking and gently filing the surface, and requires persistence to succeed;
• Cryotherapy: Application of liquid nitrogen to freeze the lesion, usually repeated every two to three weeks over several sessions;
• Observation: Appropriate for warts that cause no trouble, and particularly reasonable in children;
• Laser, radiofrequency or electrocoagulation: Selected alternatives for warts that have resisted simpler treatment, rather than first-line choices. All destroy tissue and can scar;
• Surgical excision with histology: Reserved for atypical lesions or where malignancy is suspected.

Self-removal is not recommended due to risks of bleeding, infection, and viral spread. Any treatment must be conducted under sterile conditions by trained professionals.

Prevention of Common Warts

Preventive strategies focus on reducing HPV exposure, supporting immune function, and maintaining skin integrity. Key recommendations include:

• Maintain personal hygiene: Avoid sharing personal items, especially in communal environments like gyms or swimming pools;
• Treat conditions that damage the skin barrier, such as eczema, since intact skin is the main defence against the virus;
• Protect skin from trauma: Keep cuts and grazes covered, and minimise chronic friction and irritation;
• Limit direct contact: Avoid touching known warts (yours or others) and wash hands frequently;
• Cover a wart before using shared gym equipment or a swimming pool, and wear footwear in communal changing areas.

With early diagnosis, proper management, and responsible self-care, most cases of verruca vulgaris can be effectively controlled—and the chances of recurrence or complications minimized.