The history of the use of cryosurgery in dermatology

Cryosurgery (meaning cold handiwork) is also known as cryotherapy, cryocautery, cryocongelation and cryogenic surgery. Cold therapy has a long history of being used for analgesia and anti-inflammatory purposes, going as far back as the ancient Egyptians. However, during the past 200 years, it has evolved into a more specific use, namely the destruction of tissue in dermatology.

Liquid air, oxygen and carbon dioxide snow was initially used as the cryogen for procedures. In 1929 dermatologists Irvine and Turnacliffe reported using liquid air treatment for seborrhoeic keratoses, senile keratoses, lichen simplex, poison ivy dermatitis and herpes zoster. They found liquid oxygen very useful for warts, declaring that `it offers a practically sure, quick and painless method for removal of all types of warts, including the plantar type'. In 1950 liquid nitrogen was found to have similar properties, but without the explosive potential of liquid oxygen, and became the cryogen of choice. Liquid nitrogen to this day remains the most popular refrigerant for removing both benign and malignant skin lesions. However, for benign lesions, N 2O has gained popularity in recent years, for it’s ease of use.

Initially, cryogens were painted onto the skin or applied using swaps. However, devices which allowed the cryogen to be sprayed directly onto the skin were already being developed in the early 1900’s, with hand held liquid nitrogen sprays being an approved method of cryosurgery around the 1950’s.

Cryosurgery has remained popular in dermatology, due to it’s effectiveness and low risk of scarring. Research has shown that collagen cells in the skin remain largely unaffected by cryosurgery, explaining the low risk of scarring after this procedure, even after deep freezes. Melanocytes were found to be the cells most sensitive to freezing, hence the risk of white spots after treatment. However, this risk remains very low when treating superficial benign lesions for cosmetic reasons, due to melanocytes being located at the basal layer/bottom layer of the skin.