What is cryotherapy?

Cryotherapy is an elegant treatment for small skin problems such as the removal of warts and minor benign skin lesions. In comparison with the surgical removal of skin lesions, cryotherapy gives a better aesthetic result.

When skin lesions are removed surgically, there is a cut through all layers of the skin and that causes a permanent scar afterwards. Cryotherapy on the other hand, is based on tissue destruction of only the upper layers of the skin. The tissue that is killed is replaced from the bottom by new tissue.

After the cryotherapy, the treated skin is red. Afterwards, there is usually a crust of dead tissue. This crust falls off after 2 to 3 weeks and then you see the newly formed skin. With the loss of the piece of skin, the skin lesion that you wanted to get rid of disappear too. The new skin is initially different in color than the skin around (hypopigmentation). This color difference decreases over time. Just like with a burn wound, in the summer you must protect this new piece of skin against the sun.

Cryotherapy is performed by means of a special instrument, the cryopen. Nitrous oxide freezes about 3 mm from the top layer of the skin to an absolute maximum depth of 5 mm and this at a temperature of -89 °C. Depending on which head is placed on the cryopen, either the ‘spray method’ or the ‘direct contact method’ is applied.

The first contact of the nitrous oxide with the skin can give a pricking feeling but disappears almost immediately. For sensitive people or young children, anaesthetic skin cream can be applied 30 minutes before starting the cryotherapy, but for most patients this is not necessary. By actuating the handle of the cryopen with one finger, a very accurate pulsating dosing can be done. How long the skin disorder should be kept white, with what head should be worked and what frequency of pulsation depends on the thickness of the skin and the assumed depth of the lesion. This assessment requires some experience of the doctor. Deep foot warts or slightly larger skin lesions should be treated several times, each time with 2 to 4 weeks between treatments. After all, the dead skin must first be removed before the next session can be done. In this way, the treatment can be carried out a bit deeper in the skin.

Compared with the old cryo method (the method with cotton swabs and a container of liquid nitrogen at -196 °C), the treatment with the cryopen clearly offers advantages. After all, a cotton swab is not accurate and can not be dosed precisely. Because too much skin freezes around the lesion, this can sometimes be quite painful. It is known that liquid nitrogen can sometimes cause scarring if the freezing time has been too long.

There are several cryopens on the market. The pen I use is a professional pen, made in Onsala, Sweden. I have been to Onsala myself to learn how to use the pen in a correct way.

Which skin disoreders can be treated with cryotherapy?

Many skin problems can be treated with cryotherapy such as:

The common wart or hand and foot wart (verruca vulgaris or verruca palmaris and verruca plantaris)

Warts are benign local skin thickenings caused by infection of the lower skin layer with a wart virus, the human papillomavirus or HPV, the majority of HPV subtype 27, 57, 2 or 1.

Hand warts are cauliflower elevations in the skin. They feel a bit harder and rougher than the surrounding skin.

Foot warts are often sunk in the surrounding skin. You recognize them by the interrupted skin lines. Black spots can be seen in the wart. These are small cracked blood vessels. Sometimes it may be necessary to scrape off some callus to see the wart more clearly. Foot warts can sometimes spread so that they become mosaic warts.

Warts in the face are sometimes filiform but, like warts on the body, can be rather flat.

How the infection happens is not known with certainty. It is assumed that the infection occurs through a small wound in the skin, possibly through contact with contaminated skin or contaminated objects.

Not every infection results in the formation of a wart. This is also dependent on the immunity of the infected person. Why some people do and why others do not develop warts is not yet known. Nor is it known why in some people warts sometimes disappear spontaneously over time and this does not happen to others. If hand or foot warts spread very quickly, this may indicate a problem of immunity and this needs to be examined.

Warts are benign. They are not dangerous, yet annoying. They are not beautiful, they are contagious and can sometimes infect and become painful.

Treatment can be done in 2 different ways:

  • There is home treatment with a product based on salicylic acid. The product must be applied again and again every evening for 2 to 3 months until the wart has disappeared. Before applying, the softened skin must first be carefully removed. Salicylic acid is an acid and gives a burning sensation when applied. The treatment is thus long and time-consuming and the many patches that are needed can cause skin irritation. A small bottle of salicylic acid costs 8 euros and will not be reimbursed by your health insurance.
  • There is treatment by the General Practitioner through cryotherapy. Cryotherapy is reimbursed by your health insurance.

Callus, corns (clavus)

Skin that has a lot to endure defends itself by becoming thicker. This horny layer thickening is called callus. If you are renovating your house, you will have to deal with calluses on your hands.

Callus on your feet is usually due to too high local pressure caused by closed shoes or high heels. Callus is also caused by standing deviations of feet or toes. Locally, this thickened skin can grow inwards under the influence of the too high local pressure. This ingrown callus is called corn or clavus. It can be very painful.

Sometimes the difference with a foot wart is hard to see. By removing calluses, the characteristic black dots appear on foot warts. In the case of corns, the callus will become visible. Callus on the feet is removed by a pedicure. The pedicure will refer you to your doctor if the callus is too deep, if a footwart appears or if an infection emerges.

After the pedicure treatment, a callus can be treated in two different ways::

  • It can be cut out with a knife. There is then a hole in the skin that slowly heals.
  • It can be treated with cryotherapy.

Pearl like warts, water warts (moluscum contagiosum)

Pearl like warts, are firm, pearly, shiny, flesh-colored nodules on the skin with a central depression.

They are caused by a skin infection with the Moluscum Contagiosum virus. The Moluscum Contagiosum virus is a virus of the genus of the Moluscipox viruses, a subdivision of the Poxviruses. Another genus of the Poxviruses is the genus of the Orthopox viruses with the most famous member Variola virus, the causative agent of smallpox which is eradicated worldwide since 1980. Do not confuse the smallpox with chickenpox caused by a Herpes virus.

Pearl warts are very contagious. Contamination occurs through skin to skin contact or through contact with contaminated objects. Scratching and fiddling promotes its spread, which is why they usually occur in groups and can also occur in the genital region. In children with eczema, pearl warts can become very numerous very quickly and in turn cause a worsening of the eczema. Adults sometimes have only one pearl wart, but sometimes also very much spread over their entire body. Especially in case of immune disorders this is the case, then lesions up to 2 cm in diameter are seen. They can occur anywhere on the body, even on the face.

Pearl warts can disappear spontaneously after a year or two, but it can also take a few years longer. In case of an underlying immune problem or when taking medication that suppresses immunity, you do not have to count on spontaneous healing and in the meantime it is very contagious. Contamination within the family is almost unavoidable, even if you keep the towels, clothes and bed linen well separated. Pearl warts can infect and therefore give lasting scars. They can be a source of psychological burden for children.

You should seek treatment as quickly as possible, especially if several pearl warts are visible from the beginning, and certainly with children suffering eczema. Eczema and pearl warts need to be treated simultaneously and the eczema must be treated with a cortizone ointment. In case of bacterial contamination, the infection is treated first before the pearl warts are treated. In older people it must be checked whether the pearl wart instead is not a skin cancer. If patients are covered with pearl warts, it is best to check the immunity. Sometimes it is then decided to wait. This can also be an option to be defended in case of warts in the face.

Treatment can be done in two ways:

  • After application of a skin anesthetic ointment, half an hour in advance, spooning out the central part of the pearl wart. The disadvantage of this method is that it can give small scars.
  • Treat with cryotherapy. Usually you have to come back several times.

There is no miracle solution for pearl warts. Don’t wait too long to start treatment.

Genital warts (condylomata acuminata)

Genital warts are treated by a dermatologist, gynecologist or an urologist, not by the family doctor. They are cauliflower-like or flat flesh-like lesions that occur on the skin around the anus, around the vagina, on the penis or on the scrotum. They can also be located on the mucous membrane in the vagina, in the anus or in the urethra.

They are caused by types 6 and 11 of the Human Papilloma Virus (HPV). These are therefore virus strains other than those that cause hand and foot warts. The types of viruses that cause hand and foot warts can not cause genital warts and the types that cause genital warts only cause warts in the genital region and not elsewhere on the body. HPV is a virus with more than 100 different types. Still other types of HPV than those that cause warts are carcinogenic and can cause cervical cancer in women (type 16 and 18 of the HPV are responsible for 70% of the cervical cancers) and in males cause penis cancer or cancer of the anal region. They also cause throat cancer through oral sex.

HPV is a very contagious virus. Contamination usually occurs through sexual contact, but not always. Contamination can also occur through skin to skin contact and HPV can also be transmitted through the fingers or exceptionally even through contaminated wet towels or by sleeping in the bedding where someone with genital warts has slept naked. As a result, we sometimes see genital warts in young children. Condoms do not stop the contamination, because a condom can not cover all of the infected skin. It is estimated that 80% of the adult population has ever become infected with some type of HPV in their lifetime. It is the most widespread STD.

Not everyone infected with HPV type 6 or 11 develops genital warts (this also applies to the carcinogenic types of HPV, ie not everyone who gets infected develops cancer). If so, we see them appear about 8 weeks to 1 year after the infection. Their size varies and also their extension. In patients with an HIV infection they can become very large and expand very quickly, possibly even degenerate into a squamous cell carcinoma.

The diagnosis of genital warts is made by examining them visually. In men who are infected (and thus carriers of the virus) but who do not develop warts, so far it can not be diagnosed. There is no test for them yet. For women, on the other hand, there is a test. When making the smear you may ask to test whether you are infected and with what type of HPV (type 6 or 11 or one of the carcinogenic types). This test is not yet reimbursed by your health insurance and costs about 35 euros.

Vaccination is possible. Even if you test positive for only one type of HPV, it may still be useful to get yourself vaccinated with Gardasil 9®. Currently 9 different types are included in the vaccine. If you are infected with one of these, you still can protect yourself against the 8 other types included in the vaccine. Disadvantage is the high cost of the vaccine (around 400 euros). Currently there is only reimbursement for Gardasil 9® for girls between 12 and 18 years old who have not yet been vaccinated with Cervarix® or Gardasil 4®. Another disadvantage is that the vaccine does not protect against all types of the HPV virus. Types 6 and 11 are responsible for probably 90% of all genital warts. Apart from the vaccination you can only try not to get infected by having as few different bed partners as possible. The condom does not protect against warts that are outside the condom. Even the female condom, which is larger in size, still can not adequately protect.

Treatment is best done as soon as possible to prevent the spread of the warts over the entire genital area.
Treatment can basically be done in two ways or the combination of these two ways:

  • By applying immunomodulatory oitment for several months
  • By means of cryotherapy

The treatment can be very disappointing with recurring warts that have to be treated again and again. Sometimes cutting away of the warts may be required under anaesthesia.

What also belongs to the treatment is informing your bed partners of the past year. This can be done anonymously because not everyone who is infected also gets warts and the other person might not know that he is infected. But also carriers who do not show warts themselves can pass the virus on again. Avoiding sex with your current bed partner is not effective as a preventive method. Before the warts are visible, you probably already have infected each other. The immune system is usually able to control the virus after a few years, with disappearance of the warts as a result. But the virus may never disappear completely from your body. Sometimes you see them pop up again after years. This is not proof of infidelity from your bed partner.

Old age pigmentation spots (lentigo solaris)

Lentigo solaris, also called lentigo senilis, old age spots or pigmentation spots, are known benign skin spots that arise with age, especially on the sun-damaged skin. They are evenly pigmented brown, sharp, oval or erratic and flat. They vary from a few millimeters to a few centimeters. Such a stain occurs when the melanocytes deep in the epidermis produce too much pigment. The stains are uniform in color. If they start to turn whimsical, they have to be checked to see if they are not degenerating. In case of doubt, a biopsy is taken.

Treatment of these cosmetically disturbing benign age spots can be done easily by cryotherapy. However, the stains tend to reappear after a while.

Aktinic keratosis

This is a precursor of skin cancer caused by derailment of the cell division of the keratinocytes (these are the cells that form the epidermis). Aktinic keratosis occurs in elderly people with sun-damaged skin. If it is not treated, skin cancer (spinocellular carcinoma) will eventually occur. It is a spot on the skin that feels rough, flaky, becomes a small wound, and does not want to heal.

Small lesions can be treated by cryotherapy (ie by destruction of the affected tissue). More extensive lesions are treated by a cytostatic ointment such as eg Efudix® ointment. After the treatment, the skin must regularly be checked. In case of doubt, a biopsy is required.

Old-age warts (seborrheic keratosis)

Old-age warts are often skin-colored, tan or gray-brown with a rough, oily-looking surface. They are also called fatty warts for that reason. Later they become thicker and bigger, and they look more bumpy or crumbling. It looks like they are on top of the skin and are easy to scratch, but they are firmly attached to the skin. Old-age warts can appear at the age of 20. At a later age, 90% of people have old-age warts on the face, neck, body or limbs. What the cause is, is not known. They are benign and not contagious. A hereditary factor seems to play a role.

Treatment of cosmetically disturbing small old-age warts can be done by cryotherapy. Larger warts need curettage or electro-cauterization under local anaesthesia, or treatment with a CO2 laser.

Benign blood vessel swelling

Small pinhead-large benign blood vessel swellings that are cosmetically disturbing can be treated with cryotherapy.

Small skin appendages or fibroids

Small skin appendages can be treated with cryotherapy. This usually does not work with larger skin fibroids located deep in the skin. Electrocoagulation works better for this. Clearly stalked fibroids can be removed by sterile scissors, in combination with cryotherapy.