What causes warts on feet?

Warts are quite scary for children because they can spread on their own, in other words, they are contagious. Another notable feature of warts is that they are not like colds or fevers that come and go suddenly. Warts have an incubation period, and during this period we cannot see any changes in the patient's body at all. The feet are far away from our hands and are wrapped in shoes all day long. What are the causes of warts on the feet?

Warts are growths on the skin caused by the human papillomavirus. It is more common in children and young people, with an incubation period of 1 to 3 months, and can spread by self-inoculation. The virus exists in the spinous cells and can promote cell proliferation and form wart-like lesions. According to clinical manifestations and locations, they are divided into common warts, flat warts, plantar warts, genital warts (condyloma acuminatum), oral warts, pharyngeal warts and epidermodysplasia verruciformis.

Warts are caused by infection with the human papillomavirus. It can be transmitted through direct or indirect contact. Anal and genital warts are mostly transmitted through sexual contact. Trauma or skin damage is an important factor in HPV infection. The course of warts is closely related to the body's immunity. The incidence of warts is increased in patients with immunodeficiency, such as kidney transplant recipients, malignant lymphoma, chronic lymphocytic leukemia and lupus erythematosus. However, the mechanism by which warts persist in relatively healthy people is still unclear.

Clinical manifestations

1. Common warts

Traditional Chinese medicine calls it "thousand-day sores", commonly known as "warts" or "warts". Common warts initially appear as pinpoint papules, which gradually grow to the size of a pea or larger, are round or polygonal, have a rough, thorny surface, are hard, and are grayish yellow, dirty yellow, or dirty brown in color. They continue to develop and proliferate in a papillary manner. Bleeds easily when rubbed or hit. The initial outbreak is usually single, which remains unchanged for a long time or continues to increase in number. Adjacent ones merge with each other and can sometimes be self-inoculated.

It often occurs in adolescents, usually with no symptoms but occasional tenderness. Common warts can occur anywhere on the body, especially on the fingers, backs of hands, edges of feet, etc. The course of the disease is chronic, and about 65% of common warts can disappear naturally within 2 years.

2. Plantar warts

It is a common wart that occurs on the soles of the feet. Trauma and friction are its causes, and excessive sweating of the feet is also related to it. It initially appears as a small shiny papule, which then gradually increases in size, with a keratinized, rough and uneven surface, gray-brown, gray-yellow or dirty gray in color, round in shape, with clear boundaries, and surrounded by a slightly higher and thickened keratin ring. It often occurs at the pressure points on the heel, metatarsal heads or between the toes. Patients experience varying degrees of pain, which has a chronic course and may subside spontaneously. It is generally believed that the disease is more likely to disappear in children than in adults, while it is less likely to disappear in those with excessive sweating or metatarsal abnormalities.

Common warts occur on the palms and are called palmar warts. Their clinical manifestations are similar to those of plantar warts.

3. Flat warts

It mainly affects adolescents and mostly occurs suddenly. It is a flat, raised papule ranging in size from rice grains to mung beans, with a smooth surface, hard texture, light brown or normal skin color, round, oval or polygonal, large in number, mostly densely packed, and occasionally arranged in strips along scratches (isomorphic reaction). There are generally no subjective symptoms, and there may be slight itching occasionally. It often occurs on the face, back of hands and forearms. The course of the disease is chronic. Sometimes it disappears suddenly on its own, or it may last for many years without leaving any scars after healing.

4. Perianal and genital warts (genital warts).