For nearly the past 30 years, I have specialized in pediatric and adult reconstructive foot & ankle surgery and dermatology of the lower extremity. I have written two textbooks on surgery of the lower extremity and two textbooks on dermatology of the foot & ankle^(1-4). Consequently, during this time, I have had the opportunity to treat many patients with stubborn foot, ankle and leg skin conditions and I have used a large number of treatment modalities for these problems. Whenever a particular skin lesion is resistant to treatment or appears somewhat atypical, it is very important to biopsy it and obtain a dermatopathology diagnosis. When the diagnosis is one of the benign lesions (acrochordon [skin tag], actinic keratosis, dermatofibroma, molluscum contagiosum, nevus, punctate porokeratosis, seborrheic keratosis, stucco keratosis or verrucae) it may be removed by a variety of techniques. One of the most useful procedures is cryotherapy, sometimes called cryosurgery. I have used a large number of different types of cryotherapy at one time or another, such as, liquid nitrogen (both the handheld unit and canister tank), carbon dioxide “snow” (Kidde^TM- CO₂), as well as Histo-Freeze® and Verruca-Freeze®.

In my opinion, the CryoProbe^TM handheld unit from Cryosurgical Concepts, Inc.,  is preferable to all of the other types of cryotherapy devices that I have used in the past.  Unlike the CryoProbe unit (N₂O), the liquid nitrogen units (N2) are large, expensive, bulky and the cryogen is too cold (-320°F); and yet, in contrast, the Histo-Freeze and Verruca-Freeze units (dimethylether and propane) are not cold enough, -67°F and -90°F respectively. The CryoProbe^TM produces a fine microstream of nitrous oxide (N₂O) at -127°F. This unit is great for the treatment of children and adults alike. I have been so impressed with the CryoProbe^TM  that I recently became a consultant for the company and look forward to answering questions or handling any issues regarding the use and options for this instrument.

The use of commercially available over-the-counter cryotherapy devices are all about -70°F and difficult for lay persons to get adequate detailed application. Therefore, it is my opinion that these units should be discouraged due to the potential for serious skin damage⁽⁵⁾ .  Patients and parents should be advised to see a foot & ankle specialists for the treatment of all skin related conditions.

1.        Butterworth, R and Dockery, G.L.: A Colour Atlas and Text of Forefoot Surgery, Wolfe Publishing Ltd, London, 1992.

2.        Dockery, G.L.: Cutaneous Disorders of the Lower Extremity,  W.B. Saunders Co., Philadelphia, July, 1997.

3.        Dockery, G.L., Crawford, M.E.:  Color Atlas of Lower Extremity Dermatology,  Lippincott-Raven Publishers, Inc., Philadelphia, 1999.

4.        Dockery, G. L., Crawford, M.E.: Lower Extremity Soft Tissue & Cutaneous Plastic Surgery, Elsevier Science Limited (Saunders), Oxford-Philadelphia, January 2006.

5.        Sammut SJC, Brackley PTH, Duncan C, Kelly M, Raraty C, Graham K: Frostbite following use of a commercially available cryotherapy device for the removal of viral warts, Dermatology Online Journal 14 (6): 9, 2008.

G. Dock Dockery, FACFAS, DPM 

Seattle, WA