Acne: Part 1

On Day two of MauiDerm 2014, our panel of experts in the field of Acne presented new insights and new data that may help the practicing dermatologist improve the overall outcomes of patients in their practice.

Isotretinoin Issues

Written by Judy Seraphine

Dr Guy Webster lead off the discussion by discussing some of the hot papers in acne in 2013 that help with either the understanding of acne or the treating of it. The first paper, published in JAMA Derm, discusses high dose isotretinoin and whether or not it is safe and effective. Traditionally, data demonstrated that the 120 mg/kg dose has a 20% relapse rate. One thing that we have figured out is that if someone has really bad acne as a child, they will most likely have a relapse later and likewise, patients who had really severe acne on isotretinoin will likely relapse. Two recent studies showed that the more accutane than we typically use may decrease the relapse rate. Another paper, a retrospective study, looked at patients on a really, really high dose isotretinoin versus those on high dose isotretinoin and the researchers found the really high dose had a lower relapse rate, but it was still somewhat high. As dermatologists, we have to consider that there may be a difference in how we define relapse and prospective head-to-head studies need to be done.

Another paper, published by Drs Webster and Leyden in the JAAD, looked at a new form of isotretinoin that doesn’t require a dietary adjustment. We have known for years that isotretinoin requires a fatty meal as there is decreased absorption on an empty stomach. Dr Webster feels that the most common cause of isotretinoin resistance is due to patients taking the drug on an empty stomach. Data exist demonstrating that high-fat meals enhance the absorption of the drug, yet this new form of isotretinoin may be a viable alternative with regards to dietary change and acne outcomes.

What about P. Acnes? Dermatologists should remember that there are many strains of P. Acnes that have subtle differences, but there was no difference in where they developed. A recent paper reported that they found two strains of P. Acnes. The type 1a strain of P. Acnes predominates in inflammatory acne lesions and 1b in non-inflammatory. Some strains are associated with inflammatory acne; however, this association is a trend and not an absolute.  The question is whether this is due to ecology or virulence? There are two possibilities: 1a is more pathogenic and can survive better in an inflamed mileu. It’s important to look at how strain 1a is different from strain 1b.