Smoking causes acne in women, reported the Daily Mail . But rather than normal acne, it causes non-inflammatory acne, characterised by “blocked pores and large blackheads but less inflamed spots than normal acne”, the newspaper explained. The report is based on the findings of a study of 1,000 women that found that smokers who were acne sufferers in their teens were four times more likely than non-smokers to develop acne in adult life.
This story is based on a letter in a medical journal discussing the findings of a cross-sectional study. Without full details, the quality of the study cannot be fully assessed. Cross-sectional studies, however, cannot establish causation. At best, the study has highlighted a link between smoking and acne that will need further investigation. The findings are not robust enough to suggest that smoking is a cause of acne.
The study was carried out by Bruno Capitiano of the Paediatric Dermatology department, and colleagues of the Laboratories of Skin Physiopathology, Clinical Pathology, Immunology and Histopathology, of San Gallicano IRCCS, Rome. It was published in the peer-reviewed medical journal British Journal of Dermatology .
The article is a letter where the authors have discussed their recent cross-sectional study into smoking and acne. The researchers describe a form of ‘non-inflammatory acne’ that they have seen through their clinical practice experience.
The article suggests a cross-sectional study was conducted, but does not provide many details about the study that was carried out. It says that women aged from 25 to 50 years old, who were mothers or were accompanying children to a children’s skin clinic were randomly enrolled to the study to give a group of 1,000.
The participants were asked questions about smoking habits, acne as a teenager, and hormonal imbalance, and they were examined for the presence of acne and for signs suggestive of an excess of male hormones. The acne was classed as being inflammatory (if there was a predominance of red spots around the jaw area) or non-inflammatory (if there were mostly blocked pores and blackheads on the cheeks and forehead). The researchers compared the prevalence of acne between smokers and non-smokers in the sample.
The researchers found that 18.5% of the total 1,000 women had acne. When the group was divided into smokers and non-smokers, 41.5% of the smokers had acne compared with only 9.7% of non-smokers.
The researchers report that when they asked about acne as a teenager, 47% of the female smokers who were affected when they were young had acne now, compared with only 18% of non-smokers. They concluded that of women who had acne as teenagers, smokers were four times more likely to suffer acne as an adult compared with non-smokers.
The authors conclude that non-inflammatory acne, which differs from the normal form of adult acne, is more common in smokers. They say that predisposed females, that is, those who had acne when they were young, are more likely to experience acne in adult life if they smoke. They discuss possible explanations for this, such as nicotine and other chemicals in smoke increasing the levels of skin cell turnover, causing constriction of blood vessels, a lack of oxygen to the skin, and causing oxidation reactions that alter the content of the oily substance (sebum) produced by the skin.
This article presents findings of the observations in female smokers attending a clinic in Italy. Although smoking may be a contributing factor towards acne, it cannot be concluded from this report alone that it is a cause:
There are already plenty of good reasons not to start smoking, or to give up if you do. This may be one more, and one of particular relevance to a group whose smoking remains very high, probably mainly because of weight worries. Tempting though it would be to use this piece of evidence, a letter is not sufficiently robust evidence for immediate action.