If you experience acne breakouts after using ecstasy, consider that one side effect of ecstasy use is typically staying up all night, a massive disruption of the cirdadian rhythm. Sleep deprivation can cause acne on its own, never mind the variety of ways that drug use affects your hormones and body chemistry.
There is limited research on ecstasy and dermatological conditions. In this tiny study, dermatologists looked at two patients who experienced reddish pimples after taking acne.
A rash that looks like acne but is a separate condition appears to be a common side effect of acne use, according to German dermatologists.