MADRID – Do you ask your acne patients if they use cannabis? And if they say yes, do you suggest they consider giving it up? Dermatologist Delphine Kerob, MD, believes you should.
Bruce Jancin/MDedge News
Dr. Delphine Kerob
In a late-breaker session at the annual congress of the European Academy of Dermatology and Venereology, she presented . One of the biggest surprises in this first-of-its-kind study was the finding of an association between cannabis use and acne: 21.1% of patients with physician-diagnosed acne were users, compared with 16.6% of controls without acne.
“I think as dermatologists we should ask these kinds of questions when we manage our patients because this may influence the course of their acne,” observed Dr. Kerob, who is the international medical director for Vichy Laboratories in Paris. The survey was sponsored by the company.
This was an Internet-based survey of 2,826 acne patients and 3,853 age- and sex-matched controls without acne. It was conducted in Canada, France, Germany, Italy, Brazil, and Russia.
The survey comprehensively addressed for the first time what lead investigator Brigitte Dreno, MD, PhD, professor and head of dermatology at Nantes (France) University Hospital and EADV Scientific Programming Committee Chair, has previously called the “acne exposome.” The exposome is essentially everything in a patient’s external and internal environment – other than genetics – that influences the occurrence and severity of the disease (J Eur Acad Dermatol Venereol. 2018 May;32[5]:812-9).
The survey probed the six major categories of exposome factors as defined by Dr. Dreno and coauthors: nutrition, air pollution, lifestyle and psychological factors, medications, skin care products, and climate. Here are the highlights:
Lifestyle and psychological factors. While cannabis use emerged as a novel factor linked to increased likelihood of acne, tobacco use was not – a surprising finding because other investigators had previously identified it as an acne trigger.
Feeling burdened by psychological stress was reported by 51% of acne patients and 29% of controls, for an adjusted 1.79-fold increased risk of acne.
Air pollution. Acne patients were significantly more likely to report exposure to solvent vapors, crude oil, tars, frying oil vapors, and living near an airport or close to factories with chimneys. Dr. Kerob noted that these findings are consistent with other investigators’ study of 189 residents of heavily polluted Mexico City or more pristine Cuernavaca, Mexico, with less pollution. The Mexico City cohort demonstrated an increased sebum excretion rate, lower levels of the antioxidants vitamin E and squalene in their sebum, and a less cohesive stratum corneum, along with a higher prevalence of atopic skin and facial seborrheic changes (Int J Cosmet Sci. 2015 Jun;37[3]:329-38).
Nutrition. This is a hot topic that acne patients have many questions about. Myths abound, as detailed by an expert panel including Dr. Dreno in an article entitled, “Acne and Nutrition: Hypotheses, Myths and Facts” (J Eur Acad Dermatol Venereol. 2018 Oct;32[10]:1631-7).