Warts are caused by various types of Human Papilloma Virus (HPV) which are DNA Viruses measuring about 50nm in diameter and are members of the family papovaridae.
Warts occur when the virus comes in contact with your skin and causes an infection. Warts are more likely to develop on broken skin, such as picked hangnails or areas nicked by shaving, because the virus is able to enter the top layer of skin through scratches or cuts.
There are several different types of warts which all vary in size and shape. For example, warts can range from 1mm to more than 10mm (1cm) in diameter.
The different types of warts are described below.
- Common warts
If you have a common wart it will:
be round or oval shaped
be firm and raised
have a rough, irregular surface similar to a cauliflower
often develop on the knuckles, fingers and knees
vary in size from less than 1mm to more than 10mm (1cm) in diameter
You may develop one common wart or several.
- Plantar warts
Verrucas usually develop on the soles of your feet. The affected area of skin will:
be white, often with a black dot in the centre (blood vessel)
be flat rather than raised
sometimes be painful because your body weight can force the verruca to grow back into your skin.
- Flat warts
It is possible to have between one and several hundred plane warts, which can develop in clusters. They are usually:
a yellowish colour
smooth, round and flat-topped
2-4mm in diameter
common in young children, mainly affecting the hands, face and legs
Plane warts can also sometimes develop on the lower legs of females because the human papilloma virus (HPV) can be spread through shaving.
- Filiform warts
Filiform warts are long and slender in appearance and often develop on the neck, face and nostrils.
- Periungual warts
Periungual warts develop under and around the fingernails and toenails. They:
have a rough surface
can affect the shape of your nail
can be painful
- Mosaic warts
Mosaic warts grow in clusters and form a ‘tile-like’ pattern. They often develop on the palms of the hands and on the feet.
In rare cases, may need to perform a skin biopsy to be certain.
Though skin warts can’t be prevented, there are a number of precautionary measures you can take to minimize your risk of acquiring warts. One of the most important things you can do is to wash your hands regularly. Also, try to keep your skin healthy, moisturized, and free of cuts. If you bite your fingernails or cuticles, do your best to stop. Biting nails creates an opening for virus to enter your skin. Be careful to use clean, fresh towels at the gym or in other public locations, and always wear rubber-soled flip-flops or sandals in public locker rooms and showers.