Warts are skin changes caused by viruses and show up in many different forms; plantar warts, flat warts or filiform (digitate) warts. If they are not treated early or thoroughly enough, they can spread and appear in clusters. Warts can be treated with tinctures, curettage, freezing, and laser as well. The therapy depends on the type of wart, the age of the patient and the extent of the diagnosis.

Laser ablation skin skin warts - dermatologist Dr Hero Schnitzler - Zurich-Enge

Laser Removal of Warts – Dermatologist Dr. Hero Schnitzler – Zurich-Enge

Table of contents

1. Warts in General

Warts are small, round, raised or flat individually occurring keratinization disorders of the skin. Many people have warts (verrucae). They are one of the most common benign skin tumors. It can be presumed that every individual will suffer from a wart at least once in their life.

2. Where Do Warts Appear?

Warts can appear anywhere on the body. They are mostly found on the hands and feet.

3. What Causes Warts?

A wart is triggered (mostly) by an infection with the human papillomavirus (HPV). There are well over 100 different human papillomaviruses. Warts have different appearances depending on the HP-virus that causes the wart. Most of these wart viruses are low-risk viruses. There are however individual papillomaviruses which are classified as “high-risk” viruses because sometimes they can be carcinogenic.

Both men and women are equally prone to warts. Warts often occur in childhood and another peak of the disease is observed around the age of 30. Those who are affected usually develop warts several times in their lives.

Schematische Darstellung einer Warze

The wart with the virus is supplied by the infected skin cells. @timonina – AdobeStock

4. Sources of Wart Infection

The wart-causing virus is transmitted from person to person through direct or indirect skin contact (e.g., communal swimming pools, saunas, etc.). This is also called a contact or smear infection. For this reason, warts often appear on the hands, fingers, and soles of feet.

The virus infects the outer layer of the skin cells by entering through even the smallest of unnoticed wounds like scratches and cuts.

The viruses multiply in the cell nuclei of the skin cells. The normal skin cells are “reprogrammed” to form wart cells.

Typical skin changes form for example, the round wart on the hands, the filiform wart on the face and or the flat plantar wart on the soles of feet.

From the time of the infection, weeks to months can pass before formation of warts appear.

5. What Are the Different Kinds of Warts?

Plantar Warts / Foot Warts

A wart on the foot or a wart on the sole of the foot is the most common form of wart. These warts on the foot or soles of feet can be painful at times and may affect walking.

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Warts on the soles of feet are often painful. @srisakorn – AdobeStock


Warts on hands are very uncomfortable. @muro – AdobeStock

Common Warts / Hand Warts

Warts on the hands and fingers as with plantar warts on the soles of feet, are also a very common occurrence resulting from an HPV infection. They are not only annoying in daily life and uncomfortable for the affected person (shaking hands), a wart on the hand or finger can also cause pain due to mechanical stress.

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Genital Warts

Genital warts belong to the sexually transmitted diseases. They develop almost exclusively on the genitals, but also in and on the mouth.

This type of wart is never found on the hand or foot.

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Feigwarze an Lippe

Genital warts can develop in and on the mouth. @Jade – AdobeStock

Pinselwarze an Augenaussenwinkel

Filiform warts often occur on the face and eyelids. @Анастасия Стягайло- AdobeStock

Filiform Warts

Filiform warts, also called digitate warts, typically have spiky, finger-like projections or runners on their surface. They can appear anywhere on the body, and are frequently found on the neck, face and even the lips and eyelids.

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Juvenile Warts / Flat Warts

Often occur on the face and the back of hands (less often on the tops of feet). Unlike plantar warts or common warts on fingers, juvenile warts are hardly ever painful.

They usually don’t get any bigger than the size of a pin head.

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Plane Warze an Oberlid

Juvenile warts often occur on the face. @Irin Fierce – AdobeStock

Dellwarze an Kinn

Molluscum are very common in children. @Lyudmila – AdobeStock

Molluscum Contagiosum

Sometime called water warts, this type of viral skin infection occurs almost exclusively in children. It frequently spreads on the arms, legs and torso as opposed to hands and feet.

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Age Warts / Seborrheic Warts

The typical predisposition, brown-colored, hallmarked warts appear all over the body and head. Unlike other warts, they do not occur on the soles of feet or palms.

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Alterswarzen am Rücken

Age warts frequently occur on the trunk. @srisakorn – AdobeStock

Stielwarze an Hals

Skin tags frequently occur on the neck and armpits. @Duangjan – AdobeStock

Fibroma / Skin Tags

Their occurrence is also individually predisposed. These benign tissue lesions of the skin can be very different in size, shape, and color. They are particularly common on the neck, upper eyelids, armpits, and groin area.

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6. Summary Table

Tabular wart info

Autor - Dr. med. Hero P. D. Schnitzler

I am Dr. Hero P. D. Schnitzler and founded the derma competence center in Zurich Enge in 2015, which I have been managing with heart, soul and professional competence ever since.

I am a member of various Swiss and international professional societies and a long-time lecturer for aesthetic laser medicine (D.A.L.M.) at the University of Greifswald, and for the Swiss skills program FMCH laser treatments of the skin.