Cutaneous Effects of Cryogen Spray Cooling on In Vivo Human Skin

Abstract

BACKGROUND Despite widespread clinical use of cryogen spray cooling (CSC) in conjunction with laser dermatologic surgery, in vivo cutaneous effects have not been systematically evaluated. OBJECTIVE The authors characterize the in vivo cutaneous effects for Fitzpatrick skin types I through VI after CSC exposures of varying spurt durations and spurt delivery patterns (single vs. multiple spurts). METHODS AND MATERIALS Twenty‐seven normal human subjects were exposed to single cryogen spurts from 10 to 80 milliseconds, and multiple spurt patterns consisting of two 20‐millisecond spurts, four 10‐millisecond spurts, and eight 5‐millisecond spurts. Subjects were evaluated by clinical observation and photography at 1 hour, 1 day, and 1, 4, 8, and 12 weeks after CSC exposure. RESULTS Acute erythema and urticaria (1–24 hours) were noted in 14 of 27 and 3 of 27 subjects, respectively. Transient hyperpigmentation occurred in 4 of 27 subjects (skin types III–VI) but resolved spontaneously without medical intervention in all subjects by 8 weeks. No permanent skin changes were noted in any subjects. Skin reactions were more common with longer single‐spurt durations (50 milliseconds or greater) and multiple spurt patterns. CONCLUSION Acute erythema, urticaria, and, less commonly, transient hyperpigmentation were observed after CSC exposure. Permanent skin injury was not observed and is unlikely.

Thermal responses of ex vivo human skin during multiple cryogen spurts and 1,450 nm laser pulses

“…Despite the data presented in these studies, concerns have been expressed that use of MCS is more likely to induce cryo-injury than the traditional approach of a single cryogen spurt. However, these studies [8][9][10] only involved the exposure of the skin to cryogen without laser irradiation, which is inconsistent with current clinical use where the skin is exposed to both CSC and laser irradiation.…”

“…Previous in vitro [8,9] and in vivo [10] studies have suggested that multiple cryogen spurts (MCS) are safe. Despite the data presented in these studies, concerns have been expressed that use of MCS is more likely to induce cryo-injury than the traditional approach of a single cryogen spurt.…”

“…Based on the previous MCS-LPS literature [6,10], the working hypothesis is that the epidermal-dermal junction will not reach sub-zero temperatures in response to clinically relevant MCS-LPS patterns.…”

Effect of Cold Air Cooling on the Incidence of Postinflammatory Hyperpigmentation After Q-Switched Nd:YAG Laser Treatment of Acquired Bilateral Nevus of Ota–like Macules

“…Similarly, a recent study by Datrice et al 19 also found that transient hyperpigmentation occurred after cryogen spray cooling exposure in individuals with skin type III or higher, and all hyperpigmentation was resolved by 8 weeks without medical intervention.…”

Numerical Prediction of the Intracellular ICE Formation Zone during Cryosurgery on a Nodular Basal Cell Carcinoma Using Liquid Nitrogen Spray

“…This was later confirmed also by Franco et al [163] in terms of the uniformity in the protection these sprays could provide when used in conjunction with laser irradiation. Nevertheless, the reader must not forget that non-uniformities in the heat transfer coefficient over the entire spray area exist and depend on the following parameters: geometric parameters such as nozzle diameter-length [164], nozzle-to-skin distance [165] and nozzle angle [162], cryogen spurt duration [166][167][168][169][170][171][172][173], ambient pressure [174][175][176], humidity and frost formation effects [177][178][179][180], skin indentation effects [181,182], and the dynamics of cryogen spray deposition, such as cryogenic spray shape, the droplet velocity and diameter [183]. 3.…”