Cyrotherapy is an established treatment for dermatological lesions and can be used for a variety of conditions including benign lesions such as viral warts, seborrheic keratosis, sebaceous hyperplasia, haemangiomas and lentigo, and pre-malignant lesions including actinic keratosis and Bowen’s disease.
Many, if not most, GPs in the UK will no longer provide cryotherapy through the NHS for benign lesions.1 In fact, in November 2018 the NHS released the Evidence-Based Interventions: Guidance for CCGs document, which states in its update description for the removal of benign skin lesions that they ‘cannot be offered for cosmetic reasons’ and should only be offered in situations where the lesion is causing symptoms outlined in at least one of its criteria. Some examples of criteria include: the lesion is unavoidably and significantly traumatised on a regular basis, repeated infection, regular bleeding, regular pain and impacts function.2
I have found that many GPs also don’t offer treatment on a private basis, so there is certainly a gap in the market for aesthetic practitioners to do so. I believe that cryotherapy has become a more common and popular treatment in non-surgical aesthetic clinics and is a useful addition to your current treatment portfolio. In this article, I will explore the clinical aspects behind its use for treating cosmetic benign lesions, and also touch on the benefits it can bring to you from a business perspective.
Training requirements
Firstly, it’s important to recognise that the training requirements needed to identify and diagnose appropriate lesions for cryotherapy are different to those required for performing the actual cryotherapy treatment.
Diagnosis
The practitioner must have the ability to make the correct clinical diagnosis of the lesion before treating it. This requires significant dermatological training to be considered safe and usually only general practitioners with extended roles (GPwER) or dermatologists can do this. Some dermatology nurse specialists and consultant dermatology nurses who have undertaken extensive post-graduate dermatology training may, as part of their extended scope of practice, be trained and assessed as competent to assess, diagnose and treat some skin lesions.3,4
Of course, a verruca on a young person’s foot is likely to be fairly obvious, but an apparent wart in an elderly person may be a squamous cell carcinoma, a common form of skin cancer. Pigmented lesions are of particular concern as treating them inappropriately with cryotherapy can alter the histology and prolong overall time to diagnosis,5 which is crucial in melanomas.
Practitioners must therefore be trained in recognising such lesions for safe diagnosis before treatment.
Performing the treatment
If you do not have the skills in diagnosing, you could ask your patient to obtain a diagnosis from their GP (with qualifications explained above) so that you can still perform the actual treatment in your clinic.
If the lesion is diagnosed as benign, then the GP can refer to you for treatment. As mentioned, many GPs will not provide cryotherapy through the NHS nor on a private basis, so they will sometimes be relieved to have a provider they can trust to refer their patients onto.
As with many skin-related treatments that are classified as cosmetic, one does not need to be a medical professional, just trained in performing the procedure.
The practitioner must have the ability to make
the correct clinical diagnosis of the lesion before treating it
Personally, however, I only endorse that medical professionals, with appropriate training, perform this procedure in a clinical environment as there are possible clinical side effects (Table 1).6 Practitioners must have good knowledge and understanding of the equipment, treatment protocols and methods for the device employed, which can usually be obtained from your device provider. Like many treatments in aesthetics, insurance is what determines whether or not you are able to perform cryotherapy treatments, and there are several providers available.
How cryotherapy works
Cryotherapy is defined as the local or general use of low temperatures in medical therapy, and refers to the removal of skin lesions by freezing. The procedure works by cellular and vascular injury to the tissue.7 There are several methods for delivering cryotherapy, such as liquid nitrogen, those that employ vapourisation of a volatile liquid to create cooling, and others that use nitrous oxide. As my experience lies in liquid nitrogen, I will be discussing this approach. The advantage of liquid nitrogen cyrospray is that it reaches colder temperatures than other methods,8,9,10 which I find achieves superior results.
However, the disadvantages are that it requires a large storage dewar and an appropriate safe storage space,11 while other methods are more ready to hand and economical for purchase. The clinic will also require regular deliveries of liquid nitrogen to utilise this approach.
The treatment is usually delivered by a cryotherapy spray or probe that is connected to a reservoir of liquid nitrogen, which is at a temperature of -196°C. Using an open spray of liquid nitrogen creates an ice ball, the depth of which is roughly equal to the lateral spread.12 Much is known about the efficacy of liquid nitrogen,13,14 and guidelines for treatment are well established.15
What can be treated?
As mentioned above, many skin conditions can be treated using cryotherapy. The types of benign skin lesions that are suitable for this treatment include actinic keratosis, solar lentigo, seborrheic keratosis, viral wart, molluscum contagiosum, and dermatofibroma.16
It should be noted that the efficacy of treatment depends on the condition; cryotherapy for solar lentigo is considered by some to be the treatment of choice, for example,17 whilst others suggest laser may be better.18 Other lesions such as keloid scars that have been treated with cryotherapy plus steroid injection have shown positive results.19 Some conditions are easier to treat through cryotherapy than others – for example, some cells such as melanocytes are easily damaged by cold, whereas others such as fibroblasts are very resistant to cold. There is a comprehensive list of lesions that can be safely treated with cryotherapy in Cutaneous Cryosurgery.12
Treatment process
As diagnosis involves comprehensive assessment and training, and differs for each condition, I will not be discussing this in detail. Once a diagnosis has been made, cryotherapy treatment is fairly simple. An informed consent must be obtained and the side effects of cryotherapy outlined. These are outlined in the British Association of Dermatologists’ Patient Information Leaflets, which I issue to my patients (Table 1).6 Once consent is obtained, it is useful to apply a topical anaesthetic cream such as EMLA and de-bulk the most hyperkeratotic lesions before treatment. This removes the excess lesion; I often break a tongue depressor by twisting it and scraping off the excess material or use a scalpel.
There are a variety of ways to treat with liquid nitrogen and the kits supplied usually have different nozzle sizes. I find that it is useful to use the disposable ear cones that come with otoscopes as they can be cut to a lesion size to funnel the spray.
The lesion is sprayed from about 1cm away until an ice ball forms around it, which should be maintained for the number of seconds required in the protocol, which are well-established and are different for each lesion. More information on these protocols can be found in Cutaneous Cyrosurgery.21
Feathering is a method I use to blend the edges of the treatment area, which is particularly important for pigmented lesions because a white centre and a pigmented edge can otherwise form. With most benign lesions, a single freeze thaw cycle, rather than several in one treatment, is all that is required. Other methods that can be used are cotton buds and artery forceps dipped in liquid nitrogen, or the use of a solid probe, which contacts the lesion directly. Repeat treatment intervals vary.21
Why incorporate cryotherapy into your clinic?
From a business perspective, setting up a cryotherapy service is extremely rewarding as it can give your patients great satisfaction and can be extremely profitable and simple to set up, when you have the appropriate training.
Although there are other possible treatment approaches, such as lasers, for conditions like viral warts, seborrheic keratosis, sebaceous hyperplasia, haemangiomas and lentigo, cryotherapy can be a more economical option for you as a business.
Purchasing a dewar and canister costs about £2,000 and a year’s delivery of liquid nitrogen is around £400. I charge £150 for two treatments, which makes the system quickly profitable.
After the initial consultation of around 20 minutes, the actual treatment takes only seconds and the follow-up consultation takes around 15 minutes, which I usually do a month later. Note that sometimes patients need repeat treatments and a second or third may be required.
Storage and handling of liquid nitrogen is straightforward and as long as you have a safe, locked, vented area in your clinic, it is reasonable to store the dewar there.11 Filling the canister reservoir requires gloves and eye protection, but is easy and quick. A good protocol for storage has been compiled by North Devon Hospitals.18
Summary
I have found my cryotherapy equipment very useful as part of my clinic treatment portfolio and it’s a particularly good additional profit stream. When looking to offer this service in your clinic, the key point is that all skin lesions require a correct diagnosis before treatment; never treat if you do not know the diagnosis of the lesion and do not have sufficient training. It is important to be familiar with the equipment that you purchase, use the correct treatment protocol for the lesion, and ensure you obtain informed consent from your patient.
