Tobacco smokers are twice as likely to develop a debilitating skin disease, according to new research recently published in the British Journal of Dermatology.

Hidradenitis suppurativa (HS) is a chronic and recurring inflammatory disease of the hair follicles, which causes a mixture of boil-like lumps, areas leaking pus, and scarring. It is estimated to affect around one per cent of the population, and it’s difficult to predict the severity of individual cases and how they will respond to treatment.

The study was a retrospective cohort analysis, meaning that a database of medical records is examined to spot trends in a population’s health.

The database that the researchers used has data on the health of over 50 million people in America, though for this study only patients with an active status in the database over the last three years who had race, gender, and age information, as well as at least one measurement for BMI with the study period were included. Patients who had already been diagnosed with HS before the start of the study were also excluded, as were patients who started smoking after they were diagnosed with HS.

Using this information the researchers were able to split the cohort into smokers and non-smokers and calculate the incidence of HS among both groups, taking into account other factors that influence HS incidence, such as age, gender, race, and obesity.

Of the 3,924,310 tobacco smokers, there were 7,860 patients diagnosed with HS during the study period – this compares to 8,430 cases of HS among 8,027,790 non-smokers.

This equals an overall incidence among smokers of 0.20 per cent compared to 0.11 per cent among non-smokers.

Overall, incidence was highest among the following smoking sub-groups: those aged 30 to 39 years (0.35 per cent); women (0.28 per cent); African Americans (0.46 per cent), and those with a BMI greater than, or equal to, 30 (0.33 per cent), qualifying them as obese.

Although the exact mechanisms linking tobacco smoking to HS are not understood, it has been speculated that nicotine has a role in triggering the disease.

Senior author, Dr Amit Garg, commented, ‘This is the first population level evidence that tobacco smoking is a true risk factor for the development of Hidradenitis suppurativa.

What is not yet understood is whether cessation of smoking can lead to improvement in disease activity.’

Matthew Gass, of the British Association of Dermatologists, said, ‘Hidradenitis suppurativa is a recurrent and painful disease, which can have an enormous physical and psychological impact on people, as such it is very important that medical professionals and patients understand the potential causes of this condition

‘This study also builds on the existing evidence base regarding the impact of smoking on skin health. There is already evidence that it is one of the biggest factors in skin ageing, and that it can increase the chances of acne scarring.’