CRD summary

This review assessed diet, face washing and sunlight exposure in the management of acne. It concluded that the evidence base on which to make recommendations is incomplete. The authors' conclusion is appropriate on the basis of the evidence presented, although the review itself had several methodological limitations.

Authors' objectives

To assess the evidence of effects of diet, face washing and sunlight exposure in the management of acne.

Searching

MEDLINE, EMBASE, CINAHL, AMED, the Cochrane CENTRAl Register and DARE were searched for articles published in English; the search terms were reported. The reference lists of retrieved articles were also checked.

Study selection

Assessment of study quality

Aspects of methodology were extracted and used in the interpretation of the results. The authors did not state how many reviewers performed the validity assessment.

Data extraction

The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction. The results were extracted as reported in each of the included studies.

Methods of synthesis

Results of the review

Seven studies assessed diet (n>4,194), eleven assessed washing (n=689) and seven assessed sunlight exposure (n=673).

In terms of methodological quality, most of the studies had a small sample size, were uncontrolled, or were not blinded.

Diet.

Two before-and-after studies and one crossover study found no association between chocolate consumption and acne, although high fat content of the placebo bar may have been acnegenic.

One cross-sectional study found no difference in sugar consumption between controls and acne sufferers, one found that 20- to 40-year-old acne sufferers were heavier (but not 15- to 19-year-olds) compared with controls, and one found that stress and self-assessed dietary quality were correlated with acne severity.

Facial hygiene and face cleansing.

Several studies found improvements in acne following the use of a medicated face wash, addition of an abrasive to the face wash, and medicated soaps. Other studies have been unable to identify the effective component of interventions.

Sunlight exposure.

Two RCTs, one CCT and two before-and-after studies found improvement associated with different light sources. One cross-sectional study found that there were more patients seen in the winter months, while another study found that a third had exacerbation of symptoms in winter, a third in summer and a third did not vary according to season.

Authors' conclusions

The evidence base for dietary, face washing and sun exposure is incomplete and rigorous trials are needed. Advice given by clinicians needs to be individualised, and both clinicians and patients need to be aware of its limitations.

CRD commentary

The review had several methodological limitations. There were no specific inclusion criteria for the participants, outcomes or study design, which means it was difficult to assess the relevance of the included studies to meet the review question. Several databases were searched to identify English language publications. Therefore, it is possible that some relevant studies may not have been identified. The methods used to minimise bias and reviewer error in all stages of the review process (selection of studies and data extraction) were not reported, while the validity of the included studies was not systematically assessed using established criteria.

The decision to combine the studies in a narrative was appropriate given the apparent differences between the studies. Many of the included studies were prone to bias which, as the authors acknowledged, limits the recommendations that can be made. In addition, the authors also considered the large placebo effect as an alternative explanation for improvement. Therefore, the authors' conclusion and call for research is appropriate based on the evidence presented in the review.

Implications of the review for practice and research

Practice: The authors stated that clinicians cannot be didactic when giving recommendations for the management of acne. Instead, advice needs to be individualised and both patients and clinicians should be aware of the limitations of management options.

Research: The authors stated that methodologically rigorous trials are needed to determine the effect of exposures on acne.

Funding

NSW Primary Health Care Research Bursary.

Bibliographic details

Magin P, Pond D, Smith W, Watson A. A systematic review of the evidence for 'myths and misconceptions' in acne management: diet, face-washing and sunlight. Family Practice 2005; 22(1): 62-70. [PubMed: 15644386]

Indexing Status

Subject indexing assigned by NLM

MeSH

Acne Vulgaris /etiology /therapy; Adolescent; Adult; Cacao /adverse effects; Diet; Female; Humans; Hygiene; Light; Male; Sunlight /adverse effects

AccessionNumber

12005009540

Database entry date

30/11/2005

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.