[Second joint position paper: Use of isotretinoin in severe acne].

Background: The use of isotretinoin is indicated in the treatment of severe acne; however, its adverse effects are important.

Objective: To update the first Mexican Consensus on the use of isotretinoin in severe acne vulgaris, which took place in 2009.

Methods: It was carried out a literature search between June 2009, and February 2015, in order to evaluate topics to be discussed; materials were sent to the experts to promote the debate among participants. The topics of interest were analyzed during the consensus with the Delphi modified method, using an instrument previously validated. 15 certified dermatologists with experience in handling acne with isotretinoin took part in the study; seven of them were involved in the previous consensus.

Results: Several cases of isolated adverse events were identified. Neither systematic reviews, meta-analyses nor comparative, randomized, controlled clinical trials were published during the observation period.

Conclusions: Isotretinoin is still the best treatment for severe nodulocystic acne. However, it must be taken into consideration its teratogenic effect on pregnant women and its association with inflammatory bowel disease, depression and suicidal ideas. Monitoring with laboratory tests is a tool for identifying possible adverse events.