Infrared camera evaluation of the cooling effect of triamcinolone acetonide aerosol

Objective: Triamcinolone acetonide spray is a topical corticosteroid indicated for the relief of inflammatory/pruritic manifestations of corticosteroid-responsive dermatoses. There are clinical reports of an antipruritic, cooling sensation appreciated upon application. This study was designed to quantify the cryotherapeutic cooling effect of triamcinolone acetonide spray. Design: Using an infrared video camera, skin surface temperature was evaluated for change upon application of the triamcinolone acetonide and two comparator ingredient components of triamcinolone acetonide: ethanol alcohol in a non-aerosolized spray and triamcinolone acetonide cream. Setting: This was an openlabel, single center, comparator study. Participants: This study enrolled 20 subjects with a diagnosis of either an acute or chronic steroid-responsive dermatosis. Ten additional controls were also enrolled. Measurements: Using an infrared video camera, skin surface temperature was evaluated for change upon application of the triamcinolone acetonide and two comparator ingredient components of triamcinolone acetonide: ethanol alcohol in a non-aerosolized spray and triamcinolone acetonide cream. Results: Across every study cohort, the average change in skin surface temperature with triamcinolone acetonide (between 16-18°C; P<0.001 for all comparisons, Figures 1 and 2) was significantly greater than the change demonstrated by both the non-aerosolized spray (between 5-7°C) and the triamcinolone acetonide cream (between 5.0-6.5°C). Conclusion: The transient temperature change of nearly 20°C with triamcinolone acetonide is most likely attributable to the refrigerant properties of the isobutane propellant of this product. Similar to other common cryotherapy methods, triamcinolone acetonide can achieve very low skin surface temperatures, which may result in localized relief of pruritus.