What is cryotherapy or cryosurgery?
Cryotherapy is a key tool in interventional dermatology. It is still a first-line treatment method despite its introduction many decades ago. The more correct scientific term in Dermatology is cryosurgery, however the general public knows the method as cryotherapy. We now use both terms equally.
Cryotherapy is a method of controlled cooling at very low temperatures with the aim of destroying unwanted damage. Therefore, its basis is in the way the body's tissues react to exposure to very low temperatures. For example, it has been observed that in general the body's cells are resistant to temperatures down to -20°C. However, at lower temperatures their crystallization and destruction begin. This observation is the basis of the treatment.
How is cryotherapy or cryosurgery performed?
We perform cryotherapy with the help of a device that stores and sprays a gas that we use to cool the lesion. This gas, the cryogen, is completely odorless and safe to inhale. The most common cryogen is nitrogen dioxide. We also use nitric oxide less often. We apply the cryogen in two ways. The first is direct spraying on the lesion. The second is with the initial cooling of a special metal probe (or cryode) and the contact of the frozen probe with the lesion.
Cryosurgery has a specific duration of cooling that depends on the type of lesion and the desired depth of tissue destruction. That is, the time of application of the cryogen determines the intensity of the treatment. During the application, the patient may feel a tingling sensation or even pain. For this reason, we often use local anesthesia before the treatment. We can repeat a second or even third cycle of cooling in the same session depending on the lesion.
Cryotherapy mechanism
Η κρυοθεραπεία πυροδοτεί τρεις αντιδράσεις στην περιοχή:
- Tissue destruction due to freezing and thawing (thawing) of the lesion
- Blockage of the tiny blood vessels that supply the lesion, which causes local necrosis
- Immune reaction of the body with mobilization of defense cells and their accumulation in the area.
All of this to the naked eye looks like a cold burn with redness and mild discomfort in the first 24 hours. This is followed by the manifestation of the reaction to the treatment. Usually in a mild cryotherapy (e.g. treatment of hyperkeratosis) it can be a thin dark crust. Also in a more intense treatment (e.g. treatment of warts) we have the appearance of a large blister in the area of the cooling. The blister is filled with serous fluid or even pus. The surrounding skin usually does not show redness.
However, in a percentage of patients who undergo cryosurgery, the reaction may be more severe. In this case, the picture resembles an infection. αλλά δεν είναι! Instead of a blister, we may see serous or pyorrhea, a wound, and swelling with pain in the area. This is seen in high-intensity applications (e.g., skin cancers) where we desire extensive tissue destruction.
What are the instructions after cryotherapy?
The care of the area after cryosurgery is largely determined by the intensity of the result. We avoid getting the treated area wet for the first 24 hours and we take simple painkillers as needed. We also protect the blister if it forms with an adhesive bandage. We also apply topical antibiotic preparations to the area. If the reaction and inflammation are intense, in consultation with the dermatologist, we take oral antibiotics for a few days.
Where can we use cryotherapy?
Cryotherapy has a wide range of applications. More specifically, it can be used to treat the following conditions in dermatology:
- Warts
- Hemangiomas
- Papillomas
- Genetical Warts
- Pyogenic granuloma
- Keloid/hypertrophic scar
- Venous lip lake
- Mucous cyst
- Seborrheic hyperkeratosis
- Bowen's disease
- Cutaneous Leishmaniasis
- Orf
- Annular granuloma
- Freckles-Brown marks
- Actinic Hyperkeratosis
- Erythroplakia of Queyrat
- Dermal horn
- Basal cell epithelioma
- Highly differentiated squamous cell carcinoma
- Kaposi's sarcoma
What are the possible side effects of cryosurgery?
Usually, the "side effects" immediately after cryotherapy are desirable. This is because the intensity of the symptoms after treatment (pain, swelling, serorrhea, pyorrhea) is also an indicator of the effectiveness of the treatment. We can say that in some cases, such as in cryosurgery of cancerous lesions, the rule "the worse at the beginning, the better at the end" applies.
The late side effects of cryosurgery may be mild atrophy in the area of the lesion and discolorations which gradually subside. Their frequency is also low. In general, as a treatment, it has excellent aesthetic results.
What are the contraindications to cryosurgery?
It is best to avoid cryotherapy in the following cases of diseases:
- Cryoglobulinemia
- Collagen diseases
- Taking immunomodulatory drugs
- Multiple myeloma
- Raynaud's disease
- Pyoderma gangrenosum
- Hemodialysis
- Severe and uncontrolled diabetes mellitus (relative contraindication)
