How are filiform warts caused?

Generally, filiform warts are mainly caused by human papillomavirus (HPV) infection, impaired skin barrier function, spread of common warts, extension of flat warts, and secondary infection from genital warts. It is recommended to seek medical attention promptly, identify the cause, and undergo symptomatic treatment under a doctor's guidance. The specific analysis is as follows:

1. Human Papillomavirus Infection: After direct or indirect skin contact with HPV, the virus invades epidermal cells and replicates, leading to abnormal cell proliferation and the formation of filiform warts. In daily life, avoid sharing personal items such as towels and clothing with others to reduce the chance of direct skin contact with the virus. Additionally, enhancing immunity through regular exercise and a balanced diet can help the body resist the virus.

2. Impaired Skin Barrier Function: When the skin is dry, frequently rubbed, or has minor injuries, the barrier function decreases, making it easier for HPV to invade and cause filiform warts. It is important to keep the skin moisturized by using gentle moisturizing products, avoid frequent scratching, and promptly disinfect any wounds with iodophor to prevent viral invasion.

3. Spread of Common Warts: Common warts are caused by HPV infection. If not treated timely, the virus may spread to other parts of the body and form filiform warts, often presenting as rough-surfaced skin papules. Patients may use medications such as tretinoin cream, imiquimod cream, and fluorouracil ointment as directed by a physician to inhibit viral replication and cell proliferation.

4. Extension of Flat Warts: Flat warts are mostly caused by HPV-3 infection and commonly occur on the face and back of the hands. Scratching may cause the virus to spread and develop into filiform warts, presenting as flat, raised papules. Patients may use medications such as recombinant human interferon α-2b gel, salicylic acid ointment, and tretinoin cream as directed by a physician to regulate local immunity and remove the warts.

5. Secondary Infection from Genital Warts: Genital warts are caused by high-risk HPV infection. If not completely treated, the virus may spread to other areas and trigger filiform warts, often accompanied by wart-like growths in the genital region. Patients may choose electrosurgical excision as directed by a physician to remove the wart tissue using high-frequency electric current, thereby reducing the risk of viral spread.

Daily care should include maintaining skin cleanliness, avoiding scratching affected areas to reduce the possibility of wart spread, and regularly changing clothes and towels while disinfecting personal items to lower the risk of viral transmission.