A new study has found that people who smoke are at a greater risk of developing psoriasis, a disease that affects the skin and joints and commonly causes red scaly patches to appear on the skin.
Researchers in the US discovered that regular smokers have an increased risk of the skin condition, which only falls back to normal 20 years after quitting.
The study, which included 79,000 nurses, also found that people with psoriasis who smoke had a more severe form of the disease.
Previous researches have shown links between smoking and psoriasis but failed to examine whether smoking occurred before the onset of the condition.
For the current 14-year study, the researchers reported 887 cases of psoriasis in nurses.
After making comparisons with women who never smoked, the researchers found that the risk of psoriasis was 37 percent higher among past smokers and 78 percent higher among current smokers.
The team also found that women who were exposed to passive smoking during pregnancy or childhood were also at an increased risk of psoriasis.
Study leader, Dr Hyon Choi, researcher at Harvard Medical School in Boston and the University of British Columbia in Vancouver, Canada, said that the findings provided a comprehensible incentive for those with psoriasis to discontinue smoking as well as those at risk of the condition.
"Beyond the potential effect on psoriasis, smoking cessation would lead to a better overall clinical outcome in psoriasis patients, who often suffer co-morbidities related to smoking," BBC quoted Dr Choi, as saying.
He added that quitting the habit may cut the level of smoke induced inflammation in the body by lowering levels of circulating immune cells.
"We have always recommended that people with psoriasis should aim to cease smoking for their general health and to help improve their psoriasis.
This study suggests that there is a stronger link between smoking and the risk of developing psoriasis and this clearly merits further research," Gladys Edwards, chief executive of the UK's Psoriasis Association, said.
"Psoriasis, however, is an immensely complex condition - there are people with psoriasis who do not and have never smoked," he added.
The study is published in the American Journal of Medicine.