Symptoms

Warts occur in a variety of shapes and sizes. A wart may appear as a bump with a rough surface, or it may be flat and smooth. Tiny blood vessels (capillaries) grow into the core of the wart to supply it with blood. In both common and plantar warts, these capillaries may appear as dark dots (seeds) in the wart's center.

Following are descriptions of the main types of warts:

• Common warts usually appear singly or in groups on the hands, although they may grow on any part of the body. They usually are rough, gray-brown, dome-shaped growths.
• Plantar warts can develop on any part of the foot. Sometimes dark specks are visible beneath the surface of the wart. When pressure from standing or walking pushes a plantar wart beneath the skin's surface, a layer of thick, tough skin similar to a callus develops over it. As the callus and wart get larger, walking can become painful, much like walking with a pebble in your shoe. Multiple plantar warts can form in a large, flat cluster known as a "mosaic wart."
• Flat warts are usually found on the face, arms, or legs. They are small (usually smaller than the eraser on the end of a pencil), and there are usually several in one area. They have flat tops and can be pink, light brown, or light yellow. Flat warts are often spread by shaving.
• Filiform warts, a kind of flat wart, can grow around the mouth, nose, and beard area. The surface of this type of wart has many flesh-colored, finger-shaped projections.
• Periungual warts are found under and around the toenails and fingernails. They appear as rough, irregular bumps. They can affect nail growth.
• Genital warts can be extremely small and difficult to detect. For more information, see the topic Genital Warts.

Common and flat warts usually do not cause pain. But they can be bothersome and can spread easily if they are in areas that are constantly irritated by rubbing or shaving. Visible warts can be embarrassing for some people. Plantar warts often cause pain, especially if they are located over bony areas of the foot.

Other skin conditions may look like warts. These include:

• Seborrheic keratoses, which are noncancerous growths of the skin. They vary in color from light tan to black and in size from very small to the size of a coin. The growths may look waxy, pasted on, or stuck on.
• Skin tags (acrochordon), which are small, soft pieces of skin that stick out on a thin stem. They most often appear on the neck, armpits, upper trunk, and body folds. They commonly appear after middle age.
• Corns, which are areas of thick, hardened, dead skin.
• Skin cancer. Skin cancer may appear as a growth or mole, a change in a growth or mole, a sore that does not heal, or irritation of the skin.

Warts cover the lines and creases in the skin—this is one way to tell a wart from other skin conditions.