Introduction

Conducting an epidemiological study into acne using the ALSPAC study would give us a sound basis to identify further candidate exposures for development into further provocation/prevention studies. We will have strong patient and public involvement in this study to help us disseminate results and prioritise future research.

Aims

1. To study general descriptive epidemiology of acne in ALSPAC including prevalence and severity by age, sex and ethnicity using cross-sectional analyses.

2. To study the determinants of acne incidence (especially dietary factors) using longitudinal approaches

3. To study the natural history of acne e.g. the difference between those with acne early in adolescence compared to those in late adolescence using linked data from successive skin examination sweeps

4. To study the determinants of severe/persistent disease (especially dietary factors)

5. To study the consequences of having had acne such as rates of depression and time off school

Hypotheses for analytical aspects

There is an association between diet and obesity and acne onset.

The risk of severe and persistent acne is increased in those individuals with a high glycaemic index diet in late childhood and after acne has appeared.

Exposure variables

Questionnaire data via food frequency questionnaires on diet collected at 4 weeks, 6, 15, 24, 38, 54, 81, and 103 months and 13 years

Food diaries collected as part of children in focus as well as at the hands on clinics. (Three day diaries)

Food diaries collected at 4, 8, 18, 43 and 61 months and 7.5, 10.6 and 13.9 years.

We are seeking advice from a nutritional epidemiologist who is familiar with ALSPAC to develop appropriate compound variable and a suitable analysis strategy

Demographic data on those who took part in the study

Questionnaire data on other epidemiological data for example, stress and obesity

Outcome variables

Acne severity (from examined skin). Open comedones, closed comedones, red papules, pustules, nodules, fine, superficial/atrophic macular scars, deep ice pick scars, hypertrophic scars, keloid scars and any pigmentary changes were all graded on the face and chest into a few, moderate and many. The presence of acne on the back and shoulders and upper arms/buttocks and thighs was also noted but not graded. Overall, acne severity was graded as trivial, mild, moderate and severe.

Sebutape measurements if available (there may only be a few of these available in Leeds we are currently liaising with Dr. Anne Eedy who is assisting us in our search for them)

Variables that help to document the morbidity associated with having acne such as depression and time off school

Confounding variables

Age, sex, social class

Funding (not yet awarded)

1 NIHR (application closing date 16/1/13)

2 Wellcome (application closing date 08/02/13)

Our analysis of ALSPAC data, if granted, will allow us to test some hypotheses with two other cohort studies - the National Child Development Study and the 1970 British Cohort Study. Although the quality of acne data from these cohorts is limited (some examined acne data in the NCDS and only reported acne data in BCS70) they nevertheless allow some potential verification of findings generated from the rich ALSPAC study.