What are the transmission routes of filiform warts?

Generally, the transmission routes of filiform warts include direct skin contact, indirect contact with contaminated objects, autoinoculation, infection through damaged skin, and mother-to-child contact transmission. Detailed explanations are as follows:

1. Direct Skin Contact

Filiform warts are caused by human papillomavirus (HPV) infection. The virus can spread through direct skin contact between healthy individuals and infected patients. For example, shaking hands, hugging, or any close skin-to-skin contact with an infected person may transfer the virus from the patient's skin surface to the healthy individual's skin. If the skin barrier function of the healthy person is intact, the probability of infection is relatively low; however, transmission is still possible. Therefore, direct skin contact with infected individuals should be avoided.

2. Indirect Contact with Contaminated Objects

Objects previously used by infected individuals may harbor residual virus, and healthy individuals may contract the infection by touching these contaminated items. Commonly contaminated objects include towels, clothing, razors, combs, computer mice, keyboards, etc. The virus can survive on the surfaces of these objects for a certain period. Healthy individuals may become infected if they touch these contaminated surfaces and then touch their skin, especially areas with minor cuts or abrasions. Therefore, sharing personal items should be avoided.

3. Autoinoculation

Patients already infected with filiform warts may transfer the virus to other parts of their own body if they frequently scratch the affected area. The virus may adhere to the fingernails and subsequently be transferred to other body parts—especially areas with skin damage—when scratching occurs, leading to new wart growth in these areas. This self-propagation may cause an increase in the number of warts. Therefore, patients should avoid scratching the affected areas and maintain intact skin.

4. Infection Through Damaged Skin

When the skin is broken, scratched, or abraded, its barrier function is compromised, making it easier for the human papillomavirus to invade. For example, if skin is wounded and comes into contact with an infected individual or contaminated object, the virus may enter the skin through the wound and rapidly multiply, causing infection. Therefore, proper protection should be taken when skin damage occurs, avoiding contact with potentially virus-carrying individuals or objects.

5. Mother-to-Child Contact Transmission

If a pregnant woman has filiform warts, the fetus may come into contact with virus-infected skin during passage through the birth canal, potentially leading to infection. However, this mode of transmission has a relatively low probability, and most infants infected at birth can naturally clear the virus as they grow. Nonetheless, preventive measures during pregnancy should be taken to minimize the risk of viral transmission.

In addition, viruses may also exist in public places such as communal baths, swimming pools, and gyms. It is important to promptly clean the skin after contacting public facilities in these environments. Furthermore, maintaining clean and dry skin in daily life helps strengthen the skin's barrier function and reduces the risk of infection. If any wart-like growths are suspected, timely medical consultation and treatment are necessary.