Periungual warts are common growths appearing around the fingernails and toenails. They are caused by the Human Papillomavirus (HPV), a virus with many different strains. Since certain HPV types are known to cause cancer, people often worry about the potential for malignancy in these growths. This article provides information regarding the cause of periungual warts, their relationship to cancer risk, and management options.
What Causes Periungual Warts?
Periungual warts result from infection with the Human Papillomavirus (HPV). The virus enters the skin through tiny cuts or abrasions, often caused by trauma like nail-biting or picking at the cuticles. Once inside the outer layer of the skin, the virus prompts rapid cell growth, which forms the characteristic wart.
These warts are typically caused by low-risk, cutaneous HPV types, such as HPV-1, HPV-2, HPV-4, and HPV-57. These strains are distinct from the types associated with anogenital disease. The resulting growth is usually a rough, hardened bump, frequently appearing in clusters around the nail plate. Due to their location, periungual warts can be challenging to treat and may cause pain or lead to nail disfigurement.
Addressing the Cancer Concern Directly
The majority of periungual warts do not lead to cancer and are considered benign skin growths. The HPV types responsible for common warts are low-risk strains that lack the genetic potential to induce malignancy. The risk profile is determined by the specific viral strain involved.
High-risk HPV types, particularly HPV-16 and HPV-18, cause most HPV-related cancers, such as cervical and oropharyngeal cancers. These high-risk strains produce specific oncoproteins that interfere with the body’s tumor-suppressing mechanisms, leading to cellular transformation and cancer progression. The low-risk types that cause periungual warts lack this oncogenic potential.
A rare association exists between high-risk HPV types and certain periungual malignancies, most notably Squamous Cell Carcinoma (SCC). In these cases, HPV-16 is frequently detected, and the tumor may initially present as a persistent, difficult-to-treat wart. This transformation is often reported in lesions present for years. While immune suppression is a risk factor, most reported cases occur in individuals with normal immune function.
Common Treatment and Management Options
Periungual warts are difficult to treat due to their location near the nail matrix. Over-the-counter options primarily involve topical treatments containing salicylic acid. Salicylic acid works by slowly destroying the wart tissue through chemical exfoliation. Consistent, daily application for several weeks or months is required for clearance.
If over-the-counter methods are ineffective, a dermatologist can offer professional interventions. Cryotherapy involves freezing the wart with liquid nitrogen, causing a blister that sheds the lesion. This procedure often requires multiple sessions spaced a few weeks apart.
Other treatments for stubborn warts include electrosurgery, which uses heat to destroy the tissue, or laser treatment, which heats and destroys the wart cells. Immunotherapy may be used for recalcitrant cases, stimulating the body’s immune system to fight the virus. Recurrence is common regardless of the method, and treatment carries a small risk of causing permanent nail deformation.
Symptoms That Require Medical Evaluation
While most periungual warts are harmless, certain signs require medical evaluation to rule out a more serious condition, such as Squamous Cell Carcinoma. A lesion that exhibits rapid growth, persistent bleeding, or the development of a non-healing ulcer warrants professional assessment.
Other alarming symptoms include noticeable changes in pigmentation, especially dark, irregular borders or streaking under the nail. If the wart causes severe, persistent pain or is associated with nail plate failure or significant deformity, a biopsy may be necessary. Signs of secondary bacterial infection, such as pus, increased swelling, or fever, also require prompt medical attention.