Viral Warts

Overview

A viral wart is a very common condition that appears as a growth on the skin caused by an infection linked with human papillomavirus (HPV). A cutaneous wart is also termed a verruca or papilloma.

In children, 50% of reported wart cases disappear within 6 months and 90% disappear after 2 years. Adults have more persistent cases, but the majority clear up after a proper treatment is administered.

Causes and Risk Factors

Warts are caused by human papillomavirus (HPV), a double-stranded DNA virus. The infection begins in the basal layer of the epidermis, which facilitates the formation of keratinocytes and hyperkeratosis. HPV can be spread by skin-to-skin contact or by autoinoculation. Scratching or picking a wart causes viral particles to spread to other areas of the skin. The incubation period can last up to 12 months.

Wart conditions can affect anyone at any age. However, certain groups are at elevated risk. School-aged children are among the most affected. Patients with eczema are also prone to warts due to the damaged skin barrier. Individuals who are immunosuppressed with medications such as ciclosporin or azathioprine, as well as those infected with human immunodeficiency virus (HIV), may experience a chronic wart condition regardless of whether treatment is being received.

Signs and Symptoms

Cutaneous warts generally present with a hard and keratinous surface. A very small black dot may sometimes be observed at the centre of the lesion due to intracorneal haemorrhage. In dermatology, warts are grouped based on their clinical features into the following categories: common wart, plantar wart, plane wart, filiform wart, and mucosal wart.

Common warts appear as lesions with rough, papillomatous, and hyperkeratotic surfaces. They are usually found on the fingers and toes. These warts can also form around nails, which may negatively affect nail growth.

Plantar warts appear on the soles of the feet. Due to applied pressure, these warts grow inward, which may lead to callus formation. In rare cases, plantar warts may lead to the formation of verrucous carcinoma.

Plane warts appear as clusters of flat lesions. They are commonly found on the face, shins, and hands. These warts may be caused by shaving or scratching, which can give them a linear feature.

Filiform warts have a thread-like appearance and are usually found on the face.

Mucosal warts are also known as oral warts. They appear on the lips and inside of the cheeks. They are considerably softer than other types of warts.

Diagnosis

Warts are diagnosed according to their unique clinical features. When the top surface of the wart is removed, pinpoint dots are expected to be observed. A dermatoscope may be applied to distinguish viral warts from other lesions such as skin cancer and seborrhoeic keratosis. In rare cases, a skin biopsy may be performed to confirm the diagnosis.

Treatment Options

Treatment of warts is complex and may be uncomfortable for some patients depending on pain tolerance. In order to remove warts, the patient's immune system must be stimulated to attack the wart virus.

Topical treatments are very common. They consist of wart paints containing salicylic acid, which helps to remove the dead surface of affected skin cells. Podophyllin, a cytotoxic agent, may also be used; however, it is not recommended for pregnant women or those planning to become pregnant.

Wart paint should be applied daily to the affected skin, with care taken to avoid contact with healthy surrounding skin. Before application, the wart should be softened by soaking in a warm water bath. The top surface of the wart should then be rubbed with a pumice stone, after which the paint is applied. Once dry, the lesion is recommended to be covered with a bandage. This treatment method helps to reduce the size of the wart and decrease discomfort. After 12 weeks of daily applications, the majority of warts are expected to disappear.

Cryotherapy is another treatment option, consisting of the use of liquid nitrogen to destroy lesions on the superficial skin layer. After 3 to 4 months of regular cryotherapy sessions conducted once every two weeks, the majority of warts are expected to disappear.

Electrosurgery involves burning the base of the affected skin area. This method is applied to large lesions and wart lesions that are resistant to other treatments. A local anaesthetic is administered during the procedure. On average, the wound heals within a month. A permanent scar may result from electrosurgery.

When to Seek Medical Attention

Medical evaluation is recommended when warts are persistent, rapidly spreading, painful, or located in areas that affect daily function. Immunocompromised individuals should seek assessment promptly, as warts may prove more difficult to resolve in these patients. A dermatologist should be consulted if there is uncertainty about the diagnosis or if lesions display unusual characteristics that may warrant investigation to rule out other conditions.