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.

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.

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.

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 10.03.4 (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.

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.