The cause of warts

Human Papilloma Virus

Warts are caused by a virus known as the Human Papilloma Virus (HPV). The virus causes unusual and rapid growth of the skin cells on the outer layer of the skin (epidermis). The skin cells in the epidermis multiply more rapidly, which results in a hardened bulge on the skin. The appearance of a wart can vary depending on what part of the body it is, as well as how thick the skin is. Warts are often skin-coloured and feel rough, but they can be dark (brown or gray-black), flat, and smooth.

There are more then 100 different strains of the Human Papilloma virus (HPV) and at least 60 are known to cause warts. Many people carry the virus, but not everyone will develop a wart. Warts can affect any part of the body, but most often they appear on the fingers, hands, arms, and feet. Warts also may occur in the genital area. Different types of strain tend to cause warts on different parts of the body.

The virus that causes warts is contagious and can spread easily by direct contact and indirect contact from person to person or to different body parts. Direct contact through skin-to-skin and indirect contact by a surface that touched the wart and is infected. The incubation period (the time from initial infection until the wart appears) is about three to six months but warts can lie dormant for years. Even when the wart is gone, the virus remains in the skin.

Warts can occur at any age but are most common in children, young adults and people with immune system deficiencies.

HPV

How do you get infected

The wart virus loves warm, moist places like small cuts or scratches on your hands or feet. Once the virus finds a nice warm place on the skin, a wart begins to develop. Warts can grow for many months, sometimes a year or more before they are big enough to see. So, if you do get a wart, you may never know where or when you came into contact with the HPV.

Person to person

The HPV is contagious and can be passed from person to person by either direct or indirect contact. The virus can also spread from one body location to another on the same person. The virus enters the body through an area of skin that is cracked, peeling, or moist.

Immune system

Each person's immune system responds differently to the virus, and each type of wart behaves differently on the skin. For some people, warts disappear on their own, these people may develop life-long immunity to a certain strain. Others may get warts that multiply rapidly and even reappear after treatment. Even if you get infected with the virus, the virus may not develop into a wart. To keep a wart from growing back after treatment, your immune system must respond to the virus and rid your body of the infection.

Public places

The virus is often spread indirectly from person to person in public places. Swimming pools, saunas, public showers and sport centres are common places where one can get infected. As mentioned before, the virus likes warm moist places and can easily penetrate the skin if its softened or damaged. Therefore it is not recommended to walk barefoot in these places or share towels with someone else.

The amount of virus present, the location of contact, and the state of a person's immune system are all factors that determine if an HPV infection will cause a wart to form.

Signs and symptoms

Warts shouldn't usually cause you any symptoms, but you may find them uncomfortable or painful. Different types of warts develop in different shapes and sizes and appear on different parts of the body. The different types of warts can be identified by their specific appearance:

Common Wart

The common wart is a cauliflower-like, hardened and rough surface. Usually they appear in groups, mainly on the hands, knees, elbows or on the face.

Verrucas or plantar wart

Appears on the sole of the foot and is the most common wart. This type of wart is the same as the common wart but they look flatter, because they tend to grow inwards.

Flat wart

The flat wart is smooth, flat and only a few millimetres in size. It appears as a skin coloured or light brown lump. They mainly occur in groups on the face, arms and legs.

Filiform wart

Long and slender growths that appear as a long stalk on the face, neck or armpit.

Water wart

Water warts are small smooth lumps with a dent on top. They can occur anywhere on the body in large groups or clusters. The water wart mainly occurs on children up to 5 years of age and are very contagious.

Genital warts

Genital warts can be found in the genital area and are a Sexually Transmitted Disease (STD). Genital warts are transmitted by sexual contact and are caused by a different type of virus.

More about different types of warts