A study involving the world’s largest gathering of twins supports research that there is a genetic link for acne, but environmental factors may influence its severity.

The acne study, published in the Journal of Drugs in Dermatology, involved a survey of 139 identical and fraternal twins (and one set of triplets) who were attending the largest annual gathering of twins – the Annual Twins Day Festival in Twinsburg, Ohio.

The similar genetic make-up of identical twins enables researchers to separate genetic triggers for acne from environmental ones.

The twins were predominantly female with fair skin and were surveyed about their demographics, medical history, family history, social history and physical activity. They were also asked about acne incidence, age of onset, acne severity and triggers.

The proportion of concordant pairs (where both twins have acne) was significantly higher for the identical twins compared with fraternal (64% vs 49%), which supports prior studies that acne is largely due to genetics.

Study authors also analysed the identical twins for differences in their acne severity. The twin with more severe acne was more likely to report that their acne became worse due to sun exposure, cosmetic product use, sugar intake, and refined carbohydrates.

The researchers also found:
• acne was associated with polycystic ovarian syndrome (PCOS) and anxiety, reflecting other studies
• identical twin pairs with acne had a higher BMI and exercised less than those without acne
• there may also be a link between acne and asthma, but further research is needed

The authors noted their twin study provided further support for people with acne to reduce their intake of sugar and refined carbohydrates in order to decrease the severity of their acne.

Find out more about what causes acne