Verruca: Symptoms, Types, Causes and Treatment

Verruca, commonly known as warts, are a familiar sight on human skin, affecting people of all ages and backgrounds. Despite their benign nature, these small, rough skin lesions can be a source of distress, discomfort, or embarrassment. Understanding the symptoms, types, causes, and available treatments is essential for managing and preventing their spread. In this comprehensive guide, we explore all aspects of verruca with evidence-based insights drawn from the latest research.

Symptoms of Verruca

Warts typically appear as small, rough growths on the skin, but their presentation can vary depending on the type and location. Recognizing the symptoms early can help guide appropriate management and prevent transmission.

Symptom	Description	Typical Locations	Source(s)
Papule	Raised, rough lesion	Hands, fingers, knees, feet	3, 4, 5
Hyperkeratosis	Thickened, hardened skin	Sites of trauma, nail beds	5
Asymptomatic	Often painless	Most skin warts	3, 4
Pain/Tenderness	Possible on pressure areas	Soles (plantar), periungual	6, 5
Black dots	Thrombosed capillaries	Common in plantar warts	4, 9

Table 1: Key Symptoms

Common Presentations

Verruca vulgaris, or the common wart, usually presents as a rough, raised papule with a hyperkeratotic surface. These lesions may be skin-colored or slightly darker, and often have an irregular surface texture. While many warts are painless, those on pressure points, like the soles of the feet (plantar warts), can be uncomfortable or even painful when walking or standing 3, 4, 5.

Site-Specific Symptoms

• Hands and Fingers: Most common location, especially on the dorsal surface and near nails. Warts here may interfere with manual tasks or become tender if traumatized 3, 5.
• Feet (Plantar Warts): These tend to be flat due to pressure, often painful, and may display pinpoint black dots (thrombosed capillaries) 9.
• Oral Mucosa: Less common, but oral verrucae may be found on the palate, lips, tongue, or buccal mucosa, often presenting as firm papules with a rough or cauliflower-like appearance 4.
• Subungual/Periungual: Warts under or around the nails can cause nail distortion and discomfort 5.

Additional Features

• Warts can occur singly or in clusters.
• Most are asymptomatic, but pain, itching, or tenderness can occur based on size, location, and trauma.
• In immunocompromised individuals, warts may be more numerous, larger, or recalcitrant.

Types of Verruca

Not all warts are created equal. Several distinct types exist, each with unique characteristics, preferred locations, and causative HPV strains.

Type	Appearance/Location	Main HPV Types	Key Features	Source(s)
Verruca Vulgaris	Raised, rough papule; hands, knees	1, 2, 4, 27, 57	Common in children	2, 3, 4, 5
Plantar Wart	Flattened, painful, on soles	1, 2, 4	Black dots, pain	2, 6, 9
Verruca Plana	Flat, smooth papule; face, dorsum hands	3, 10	Multiple, often in lines	2, 8
Filiform Wart	Finger-like, thin projections; face, neck	1, 2, 3, 10	Rapid growth, trauma	2
Periungual/Subungual	Around/under nails	1, 2, 4, 27, 57	Nail distortion	5
Oral Verruca	Papillary, rough, oral mucosa	2, 4, 40	Palate, lips, tongue	4

Table 2: Verruca Types

Verruca Vulgaris (Common Wart)

This is the most prevalent type, characterized by rough, raised papules, typically on hands, fingers, and knees. Children are especially susceptible, and lesions often appear at sites prone to minor trauma 3, 4.

Plantar Verruca

Located on the soles, these warts are flattened by pressure and can be painful. They often feature black dots (representing thrombosed capillaries) and may be mistaken for corns or calluses. Walking can be uncomfortable 6, 9.

Verruca Plana (Flat Wart)

These are small, flat-topped, smooth papules, most commonly found on the face and back of the hands. They usually occur in clusters and may form linear patterns due to scratching (Koebner phenomenon) 2, 8.

Filiform and Digitate Warts

These are slender, finger-like projections, usually appearing on the face, neck, or eyelids. They grow rapidly and are prone to trauma due to their protruding shape 2.

Periungual and Subungual Warts

Warts around or under the nails can distort nail growth and are often painful, especially when manipulating objects. These may be particularly persistent 5.

Oral Verruca

Oral warts are less common and can appear anywhere in the mouth, but are most frequently seen on the palate, lips, tongue, and buccal mucosa. They may be mistaken for other oral lesions, so proper diagnosis is important 4.

Causes of Verruca

Understanding what causes verruca is key to both treatment and prevention. These lesions are the result of infection by specific types of human papillomavirus (HPV).

Cause	Description	Transmission Mode	Source(s)
HPV Infection	DNA virus infects basal keratinocytes	Direct skin contact	2, 3, 5
Trauma	Microabrasions facilitate entry	Minor cuts, abrasions	3, 5
Autoinoculation	Spread from one site to another	Scratching, shaving	3
Fomites	Indirect transmission via objects	Towels, surfaces	2, 3
Immunosuppression	Reduced immune defense	Increased susceptibility	2, 7

Table 3: Causes of Verruca

Human Papillomavirus (HPV)

Warts are caused by infection with HPV, a diverse group of DNA viruses. Over 150 genotypes exist, with certain types preferentially causing specific wart types. For example, HPV types 1, 2, 4, 27, and 57 are most common in verruca vulgaris and plantar warts, while types 3 and 10 are associated with plane warts 2.

Transmission Pathways

• Direct Contact: Most commonly, the virus is spread through direct person-to-person contact, especially if there are breaks in the skin.
• Indirect Contact: HPV can survive on surfaces like shower floors, gym mats, or towels, enabling transmission from contaminated objects (fomites) 2, 3.
• Autoinoculation: Scratching or shaving over a wart can spread the virus to adjacent skin, leading to new lesions 3.
• Trauma: Sites subject to frequent trauma (hands, knees, feet) are more prone to inoculation, as microabrasions facilitate viral entry 5.

Risk Factors

• Children and Adolescents: More susceptible due to frequent minor injuries and close contact 3.
• Immunocompromised Individuals: Warts are often more numerous, persistent, and resistant to treatment in individuals with weakened immune systems (e.g., HIV, transplant recipients) 2, 7.
• Occupational Exposure: Individuals frequently handling moist objects or working in communal environments (e.g., swimmers, athletes, healthcare workers) are at higher risk 3.

Treatment of Verruca

While warts are benign and can resolve spontaneously, their persistence, discomfort, or cosmetic impact often prompts treatment. Various therapies exist, ranging from topical agents to advanced immunotherapies and physical removal.

Treatment	Method/Agent	Efficacy/Outcome	Source(s)
Cryotherapy	Liquid nitrogen	70% complete response	6
Laser Therapy	Pulsed-dye laser	~66% complete response	6
Surgical Removal	Excision/curettage	Used for oral, nail warts	4, 5, 3
Topical Agents	Salicylic acid, cantharidin	Variable, first-line	2, 6
Immunotherapy	Vitamin D3, Candida antigen	High success, 60-90%	7, 8
Photodynamic Therapy	MB/IPL/PDT	Up to 43% clearance	9
NPS Technology	Nano-pulse stimulation	Effective, safe	10
Bleomycin/5-FU	Intralesional injection	45-85% efficacy	8

Table 4: Verruca Treatments

First-Line Treatments

Topical Agents

Salicylic acid and other keratolytic agents are often the first step, especially for common and plantar warts. They soften the thickened skin, facilitating removal. Cantharidin, a blistering agent, is also used, particularly in children 2, 6.

Cryotherapy

Application of liquid nitrogen freezes the wart tissue, prompting immune-mediated clearance. Cryotherapy is widely used in clinics and achieves a 70% complete response rate 6.

Physical Removal

• Surgical Excision/Curettage: Reserved for stubborn warts, periungual, or oral lesions. Complete removal with a margin decreases recurrence but may risk scarring 4, 5, 3.
• Laser Therapy: Pulsed-dye laser (PDL) targets blood vessels within the wart, leading to regression. Its efficacy is similar to cryotherapy, with a 66% complete response rate 6.

Immunotherapy

• Intralesional Vitamin D3: Stimulates local immune response, leading to clearance even in recalcitrant cases. Studies show up to 90% complete response with minimal side effects 7.
• Candida albicans Antigen: Triggers a systemic immune response, effective for multiple or resistant plane warts 8.
• Bleomycin/5-FU: Intralesional chemotherapeutic agents, especially useful for warts unresponsive to other treatments. Bleomycin shows up to 85% effectiveness 8.

Novel and Adjunctive Therapies

• Photodynamic Therapy (PDT): Involves photosensitizing agents (e.g., methylene blue) and light exposure. Shows promising results, especially in resistant cases 9.
• Nano-Pulse Stimulation (NPS): A non-thermal electrical energy technique inducing cell death in wart tissue. Demonstrated efficacy and safety in clinical trials 10.

Special Considerations

• Recalcitrant Warts: Often require combination therapies or immunomodulatory approaches.
• Children: Less aggressive treatments preferred to minimize discomfort and scarring.
• Immunocompromised: Warts may be more difficult to treat and require specialist management 2, 7.

Conclusion

Verruca, or warts, are a widespread skin condition resulting from HPV infection. While often harmless, they can cause discomfort, cosmetic concerns, and social stigma. Fortunately, a variety of treatments enable effective management tailored to individual needs.

Key Takeaways:

• Warts are common, benign skin growths caused by specific HPV types 2, 3.
• Symptoms vary by type and location, with hands, feet, and sites of trauma most frequently affected 3, 5.
• Main types include verruca vulgaris, plantar, plane, filiform, periungual/subungual, and oral warts, each with distinct features 2, 4, 5.
• Transmission occurs via direct contact, minor trauma, autoinoculation, and fomites, with children and immunocompromised most at risk 2, 3, 7.
• Treatments are diverse: topical agents, cryotherapy, laser, surgical removal, immunotherapies, and novel options like photodynamic or nano-pulse stimulation 6, 7, 8, 9, 10.
• Most warts resolve spontaneously, but persistent, symptomatic, or cosmetically concerning lesions often benefit from intervention.

Early recognition and understanding of verruca empower individuals and healthcare providers to manage and prevent these common skin lesions effectively.