Cryotherapy or Cryosurgery

What is cryotherapy?

Cryotherapy means treatment with cold. It is used to remove lesions on the surface of the skin by freezing them, usually with liquid nitrogen, which has a temperature of minus 196 degrees Celsius. Liquid nitrogen is applied by spray, metal probe or cotton bud. The frozen skin cells are destroyed, and the treated area then heals over the following weeks.

Cryotherapy is quick and does not usually need a local anaesthetic, so it can often be carried out during your consultation.

What is it used for?

Cryotherapy is most commonly used for actinic keratoses (sun-damaged skin), viral warts and seborrhoeic keratoses. It can also be used for some other benign lesions and, in selected cases, for low-grade skin cancers such as some superficial basal cell carcinomas.

Because no tissue is removed for the laboratory, cryotherapy is only used when the diagnosis is clear from examination. If there is any doubt about what a lesion is, a biopsy or excision is recommended instead.

Before your procedure

If you have private medical insurance, you will be given a procedure code. Please contact your insurer to check your cover and whether any excess applies. Please tell us if you have previously had a poor reaction to cold, or conditions such as Raynaud's phenomenon or cold urticaria, or if you have poor circulation in the legs, as cryotherapy may not be suitable or may need to be used with care. It is also used more cautiously on brown and black skin, because the risk of lasting pale patches is higher.

Try not to have cryotherapy just before a holiday or important event, as the treated area can blister and scab for several weeks.

What happens on the day?

Dr Mounsey carries out the treatment himself. Liquid nitrogen is applied to the lesion for a few seconds. The treated skin turns white and then thaws back to normal skin temperature over one to two minutes. For some lesions, a second freeze is given after the skin has thawed. The whole treatment takes only a few minutes.

Most people describe a cold, stinging or stabbing sensation during treatment, followed by a burning or throbbing feeling as the skin thaws. The discomfort is usually mild and short-lived, but it can be more uncomfortable on sensitive areas such as the fingers and around the nails.

What to expect afterwards

Cryotherapy causes a reaction similar to a small burn. Within a few hours, the area usually becomes red and swollen, and a blister, which may be clear or filled with blood, often forms within a day or so. On brown and black skin, redness may be less obvious. Swelling can be more noticeable around the eyes and on the forehead.

Over the following days a scab forms. On the face this usually falls off within one to two weeks and on the hands within about three weeks, while on the lower legs healing can take up to three months. The treated skin can be left paler or darker than the surrounding skin.

Aftercare

Keep the treated area dry for 24 hours, then wash it gently as normal. Applying petroleum jelly daily can help healing. If a blister forms, try to leave it intact. If it is large or uncomfortable, it can be gently pierced with a sterile needle to release the fluid, leaving the roof of the blister in place. Do not pick the scab. A dressing is not usually needed unless the area is likely to rub on clothing.

Paracetamol can be taken for discomfort. Contact the clinic if the area becomes increasingly painful, red, swollen or produces pus, as these may be signs of infection.

What are the risks?

The most common side effects are blistering and temporary discomfort. Changes in skin colour, either paler or darker patches, are common and can be long-lasting or permanent, particularly in brown and black skin. Scarring is uncommon, and keloid scarring is very rare. Hair within the treated area may be lost. Numbness can occur, particularly on the fingers, but usually recovers within a few months. Rarely, a slow-healing ulcer can develop, especially on the lower legs.

Not every lesion clears with one treatment, and some, such as warts and thicker actinic keratoses, may need more than one session several weeks apart.

Results and follow-up

Your clinician will advise whether a follow-up appointment is needed to check that the lesion has cleared. Please contact the clinic if the treated lesion has not cleared once the skin has healed, or if it comes back.

More information

British Association of Dermatologists patient leaflet: https://www.bad.org.uk/pils/cryotherapy

This page gives general information only and is not a substitute for a consultation. Everyone's skin is different, and what is right for you will depend on your own circumstances. If you are worried about a skin problem, please book an appointment with Dr Mounsey or speak to your GP. If you have a mole or skin lesion that is changing, bleeding or growing quickly, please seek medical advice promptly.