TREATMENTS
Cryotherapy
Freezing with liquid nitrogen destroys abnormal cells.
- Quick and inexpensive treatment
- Non-invasive treatment for some skin cancers
- Treatment for skin tags and seborrhoeic keratoses
Cryotherapy destroys cells by freezing them. It is useful for treating shallow and flat skin lesions such as superficial skin cancers, solar keratoses, lentigines and some seborrhoeic keratoses.
How cryotherapy works
Freezing at an extremely low temperature destroys cells. The damage is similar to burning. To freeze the cells, cryotherapy uses liquid nitrogen (about -196°). The nitrogen is applied either by spraying with a special gun, or dabbing with a cotton bud. This process causes water in the cells to freeze and expand, breaking the cell wall and destroying the cell. This effect applies to both normal and abnormal cells in the treated area. It leads to to redness and sometimes blisters and sores.
When the sore heals, the original skin lesion is no longer present; the aim of cryotherapy is for it to be replaced by new healthy and normal skin cells.
Cryotherapy treats only individual spots. It cannot repair large areas of sun-damaged skin. This means that the treated area may still be likely to develop further sun-related problems in future.
Cryotherapy for solar keratoses
Cryotherapy (freezing) is a simple and effective treatment for solar keratoses.
The doctor treats individual solar keratoses for 15-20 seconds each. This treatment has a high success rate and is relatively quick and inexpensive.
Cryotheapy is a good first-line treatment for solar keratoses because:
- Usually only a single treatment is required.
- Pain and discomfort settle quickly.
- Side effects such as infection and scarring are unusual.
- The cost is relatively low.
If there are many solar keratoses (more than 20 or so), cryotherapy may not be the best treatment because:
- There is a greater risk of side effects such as pain or blistering.
- Cryotherapy can only treat lesions which are visible on the day of treatment – it has no effect on solar keratoses which are still developing and not yet visible.
- If you have many solar keratoses, treatment with a cream such as fluorouracil/calcipotriol, imiquimod (Aldara), diclofenac (Solaraze) or fluorouracil (Efudix) may be a better alternative to cryotherapy.
- Other alternatives for treating a large area affected by solar keratoses include fractional laser and photodynamic therapy.
Cryotherapy for skin cancers
Very shallow skin cancers such as superficial basal cell carcinoma and Bowen’s disease (superficial squamous cell carcinoma) often respond well to treatment with cryotherapy, avoiding the need for an excision and stitches.
Because cryotherapy might not penetrate the full thickness of the skin, it should not be used to treat skin cancer unless a biopsy has already confirmed that the skin cancer affects only the uppermost levels of the skin. If a thicker skin cancer is treated with cryotherapy, the top of the skin cancer might appear to be cured while deeper cells continue to spread and cause damage not visible from the surface.
The skin cancer and a margin of 2-3mm around it are treated by repeatedly freezing for 30 seconds and thawing (three cycles). This is a stronger and more painful treatment than cryotherapy for solar keratoses, and your doctor may perform it under a local anaesthetic to reduce discomfort.
Side effects such as blistering, pain, loss of pigmentation and scarring are common.
MBBS, MA (Virtual Comm), Grad Cert Hlth Info, Grad Dip Comp Inf Sci
Depigmentation of the back of the hand following cryotherapy treatment
Conditions treated
How it’s done
The doctor uses a canister containing liquid nitrogen with a trigger mechanism. They press the trigger to release a controlled spray of nitrogen over the area to be treated.
The spray lasts a few seconds but may be repeated in bursts to keep the treatment area frozen for a total of up to 30 seconds. This may be repeated in the case of superficial skin cancers, which require three freeze/thaw cycles.
Some people find the treatment painful, but in most cases, the discomfort is mild and easily tolerated.
After the procedure
Minimal aftercare is required. Cover blisters or sores with a dressing for three days. After this, you may wish to apply silicone gel twice daily for several weeks to reduce scarring.
Don’t apply antiseptics or vitamin E cream to the treated area. These can impair wound healing.
Formal follow-up may not be required for cosmetic treatments or treatment of low-risk lesions such as solar keratoses. If a skin cancer is being treated, the doctor may request that you return for re-examination after the treated area has healed.
Learn more about cryotherapy aftercare.
Side effects and warnings
Cryotherapy treatment may fail if gentle treatment is applied (to reduce the risk of scarring).
Pigmentation changes
Cells that produce skin pigment can be destroyed by cryotherapy, causing a permanent pale area at the site of treatment. This reaction is common, but usually hard to notice in fair-skinned people. People with darker skin should be aware of the risk of reduced skin pigmentation before having cryotherapy.
In some cases, the amount of skin pigmentation can increase after cryotherapy, due to inflammation. This usually settles gradually but in some cases can be permanent.
Hair loss
Cryotherapy to hairy areas can result in permanent hair loss. For this reason, we often avoid cryotherapy treatment in the area of the eyebrows and on the hairline. Other options such as prescription creams may be better treatments in these areas.
Slow wound healing
In regions with poor circulation (typically the lower leg), cryotherapy can cause ulcers (open sores) which take a long time to heal and may be at risk of infection. Alternative treatments such as surgical removal or applying a cream may be better treatments for BCC, SCC or solar keratoses in these areas, particularly in people with vascular problems or diabetes.
The success rate of treatment with cryotherapy is variable. Gentle treatment (to avoid scarring and depigmentation) is less successful; more aggressive treatment is effective but can lead to more complications.
More infoWound infections are relatively unusual. If you think you have an infection, it's best to have your wound assessed by a doctor or nurse.
More infoIt's normal to have redness at the site of a procedure, either due to inflammation or as part of the normal wound healing response.
More info
Level up your skin health
Know more about your skin health and how it can be improved with our range of skin cancer checks and aesthetic treatments.
Get started