There are various types of warts, also known as verruca, that affect humans. These include the common wart, flat wart, plantar wart, filiform wart, periungual wart, mosaic wart and genital wart. Each type has specific characteristics that distinguish them from the other types of wart, as classified below.

Common Wart (Verruca Vulgaris)

Common warts may develop individually or in a small cluster in an area of the body. They commonly affect the knuckles, fingers and knees, but may appear on any part of the body.

Characteristics of the common wart include:

• Round or oval shaped
• Raised from the skin
• Firm, rough surface
• Variable size, with diameter from 1mm to 1cm

Flat Wart (Verruca Plana)

Also known as a plane wart, this type of wart may occur in many areas of the body including the face, neck, hands, wrists and knees. In contrast to the common wart, they are usually small and flat in shape. They can occur on their own as a single wart of in a large crop of several hundred tiny warts together.

Characteristics of the flat wart include:

• Smooth, round and flat shape
• Yellow color
• Small with a diameter of 2-4mm

Flat warts are particularly common in children, and also occur frequently on the legs of women as a result of shaving the legs.

Plantar Wart (Verruca Pedis)

Plantar warts tend to develop on the pressure points on the soles of the feet and can often cause pain when walking.

Characteristics of the plantar wart include:

• White in color with several black dots in the center.
• Flat shaped
• Painful, particularly when bearing weight.

Filiform Wart (Verruca Filiformis)

Filiform warts usually present on the neck or face of individuals, particularly around the mouth eyes and nose. They resemble a long, thin thread and usually grow in length quickly.  

Periungual Wart

This type of wart has a rough appearance and occurs under or around the fingernails or toenails. They can change the shape of the nail, which can also become very painful as a result of the wart.

Mosaic Wart

Mosaic warts commonly develop on the hand and feet, usually the palms and soles. A cluster of warts grows together to form a linear tile-like pattern, creating an appearance similar to that of a mosaic.

Genital Wart (Verruca Acuminata)

Genital warts refer to warts that develop in the groin, genital or anal areas. They can vary significantly in size and shape, with some appearing to be flat and white whilst others are bumpy and raised from the skin. In some cases, it is not possible to see the warts, despite the presence of the virus and warts.

References

• http://www.nhs.uk/Conditions/Warts/Pages/Symptoms.aspx
• https://www.aad.org/dermatology-a-to-z/diseases-and-treatments/u---w/warts/signs-symptoms
• http://www.webmd.com/skin-problems-and-treatments/tc/warts-and-plantar-warts-topic-overview