Cryotherapy, which means ‘cold therapy,’ is a treatment used to remove skin lesions using liquid nitrogen.
Nitrogen is harmless – in fact, nitrogen makes up 78% of the air we breathe - but liquid nitrogen is an incredibly cold substance. It is so cold that its boiling temperature is -196C, so it freezes the skin almost instantaneously.
Cryotherapy can be used to treat several skin lesions including warts as well as seborrheic keratoses, and it may also be used to treat superficial basal cell carcinomas (where the diagnosis is clear, and it is deemed appropriate by the dermatologist), or other forms of skin damage caused by the sun.
What is the Benefit of Cryotherapy?
Cryotherapy is quick to perform, and heals quickly, usually without needing any local anaesthetic.
Cryotherapy may be less expensive than other forms of treatment to remove a lesion, such as a superficial basal cell carcinoma, however, it will not be offered unless it is medically suitable for a patient – meaning you can only choose to undergo cryotherapy treatment if the dermatologist says it is appropriate for you.
What is the Process of Cryotherapy?
Cryotherapy does not normally require a local anaesthetic, and is performed by the dermatologist, using a spray gun to direct liquid nitrogen onto the lesion.
The liquid nitrogen is sprayed directly onto the site of the lesion until it, and a small rim around the lesion, turn white. Some patients feel a bit of sensitivity to the freezing, but it is not generally considered to be painful.
This procedure typically takes between 10 - 20 seconds, depending on the thickness and size of the lesion. The whiteness will fade as the skin thaws, usually in 1-2 minutes.
Finally, the wound may be dressed using the appropriate dressings to keep it clean and dry; and to prevent it from rubbing against clothing.
The dermatologist will indicate whether subsequent cryotherapy treatment will be necessary, and in some patients, treatment may be repeated at regular intervals as directed by the doctor.
You will be able to go home the same day and will receive information on follow-up care, which may include applying creams.
What are the Risks and Complications of Cryotherapy?
As with all medical interventions, there is a small risk of complications, and these risks will be explained by the dermatologist, who is the best trained and qualified person to avoid these events.
As it heals, the site that has been treated with cryotherapy, and the skin surrounding it may be a little sore or swollen and exhibit redness - this is completely normal. Your dermatologist will let you know which over-the-counter pain medications you can take, should you need to. Most people find the soreness to be minimal, and more of an inconvenience.
Blistering is a common side-effect after cryotherapy treatment, but they are usually harmless and typically settle down after a few days as a scab forms (scabbing may take longer to occur if treatment is on the legs). Sometimes blisters can become filled with blood (also known as a blood blister), and while this is rarer, it is still quite harmless. You will be advised what to do if these occur, and follow the aftercare instructions given to you by the clinic, which may include applying an over-the-counter antiseptic cream or ointment. If you have any questions, you can always contact our staff who will be happy to advise you.
Another common after-effect of cryotherapy is a crusty layer of skin that appears over the area that has been treated. It may be shed and then develop again, but this is quite normal and part of the body’s healing process. It is important not to pick at the wound as it is healing, as this could increase your risk of complications.
As the wound heals, you may notice the skin that has been treated becomes discoloured and can be lighter or darker than the skin surrounding it. This may especially affect people with darker skin tones, and in those patients, it is usually permanent. Your dermatologist will advise you if this is likely to occur.
Depending on the degree of freezing to the skin (both the length of time, and the frequency of treatments) and the size of the area being treated, cryotherapy can leave minor scarring, however it is typically less scarring than other forms of treatment. Patients who have had a lesser degree of freezing do not usually get permanent scarring.
Depending on your age, the location of the treatment, and how your skin usually scars, it may be more or less visible. Most scars are reddish to start and take a little time to fully heal and blend in with the surrounding skin in a few weeks.
Depending on the location of the area that has been treated, and/or the patient’s mobility, it might be more difficult to keep a healing wound clean and dry – this may elevate the risk of complications. Your dermatologist can advise if this is likely to be the case with your treatment, and will let you know if there are any special measures you should take.
While infection is quite rare after cryotherapy treatment, it is not impossible. If you experience;
It is important to contact the clinic if you are experiencing any of these complications or unexpected pain or discomfort, whether they present immediately in the days following treatment, or weeks on from the cryotherapy treatment.
In the extremely rare event that you need care urgently and cannot contact the clinic, you should contact your GP or call 111 for advice.
What is the Recovery Time and Outcome for Cryotherapy?
The area that has been treated with cryotherapy typically takes about 7-10 days to heal, but depending on the individual, complete healing can take up to 2 weeks. Most people heal quite quickly if they are in generally good health and haven’t had any complications.
Unless the dermatologist has specified that you will need a follow-up appointment, wound healing is quite straightforward, and you shouldn’t need subsequent appointments. If you have undergone cryotherapy for superficial basal cell carcinoma, you will still need to have your regular skin checks or mole mapping in accordance with the treatment plan agreed with your dermatologist.