The Skin Responses to Dimethyl Sulfoxide in Normal Human Forearm Skin

ABSTRACT

BACKGROUND: Dimethyl sulfoxide (DMSO) is a strong urticariogenic agent and a primary irritant. A DMSO test which measures erythema and wheal responses in skin after exposure for 5 min could be a simple and easy method in evaluating cutaneous irritation. Several non-invasive bioengineering methods for the evaluation of skin irritancy have been developed in recent decades. OBJECTIVE: To evaluate whether the DMSO test using filter paper discs instead of the open well with measurements of transepidermal water loss (TEWL) and erythema index (E-index) could be useful to study skin irritancy. METHODS: Twenty healthy volunteers (19-29 years, 10 males and 10 females) with no history of atopic dermatitis were included. DMSO solutions (90%, 95%, and 100%) of 60l were applied to the left volar forearm for 5 min using filter paper discs (12mm) for large Finn chamber. Visual scores (whealing scores and erythema), TEWL and E-index were measured at 30 min after removal of the filter papers. RESULTS: The number of subjects showing erythema and wheals after DMSO exposure were 6 (30%), 8 (40%) with 90% DMSO solution; 14 (70%), 15 (75%) with 95% DMSO solution; and 20 (100%), 20 (100%) with 100% DMSO solution, respectively. Whealing scores were 0.5±0.6 (90%), 1.4±1.1 (95%), 3.5±0.9 (100%), and erythema ones were 2.9±4.9 (90%), 7.7±7.2 (95%), 20.0±6.5 (100%). E-index results were 10.0±3.4 (90%), 10.9±3.1 (95%), 12.3±2.7 (100%), and TEWL values were 14.6±4.9 (90%), 21.0±8.8 (95%), 44.9±15.3 (100%). As the DMSO concentrations were increased, there were significant increases in whealing scores, and erythema and TEWL values. E-index results were not significant, but showed a rising score tendency. There were no significant differences between the males and the females. CONCLUSION: DMSO testing may be a quick and simple method to assess cutaneous irritation. Also, TEWL measurements may be more accurate and sensitive than those of E-index measurement in the assessment of erythema and wheals. DMSO testing using filter paper discs with TEWL measurement could be a useful method in the study of cutaneous irritation.