Skin reactions to pimecrolimus cream 1% in patients allergic to propylene glycol: a double-blind randomized study.

BACKGROUND

The low concentration of propylene glycol (PG) in pimecrolimus cream makes it unlikely that the cream will induce a PG-related irritant or allergic contact dermatitis.

OBJECTIVE

To assess reactions to pimecrolimus cream in patients who are allergic to PG.

METHODS

A pilot double-blind within-patient study in 20 patients, with patch testing followed by a repeated open application test (ROAT). Limitations were that patch tests and ROATs were performed on normal skin, which may be less likely to develop an allergic response than would areas of active dermatitis.

RESULTS

Positive PG patch-test results were confirmed in 16 patients. Patch-test scores were compatible with allergic reactions in only two patients. However, ROAT scores were negative for these two patients. Reactions with pimecrolimus or vehicle during ROAT were identified in three patients, but an allergic reaction was uncertain because none of these patients reacted with both pimecrolimus cream and vehicle. Reactions with pimecrolimus were significantly less frequent (p<.01) and less severe (p=.02) than with PG.

CONCLUSION

In patients allergic to PG, pimecrolimus cream showed a very low potential to elicit allergic skin reactions.