By now, most people believe they know all about the dangers of smoking and drinking. But there is growing evidence that people with psoriasis ought to think especially hard before lighting up or downing more than a few.
Smoking and alcohol use increase your risk of developing psoriasis and may make the disease significantly worse. Heavy drinking may also prevent your treatment from working or your disease from going into remission.
This is a particular problem since many people use alcohol or smoking to cope with the tough emotions—such as stress or anxiety—that psoriasis can cause.
Cigarette smoking—What's the risk?
One study led by Luigi Naldi, M.D, published in 1999, found a much higher risk of psoriasis in smokers. Dr. Naldi's group compared people with psoriasis to people with other skin conditions; as many as one in five cases of psoriasis were related to smoking.
According to Dr. Naldi, "We know that smoking affects the onset of psoriasis and its clinical appearance. Smoking about doubles a person's risk of getting psoriasis; the risk increases with the number of cigarettes smoked per day, and is higher in women than men. The risk for women who smoke more than 20 cigarettes per day is about 2.5 times greater than the rate of nonsmokers, and in men the risk is about 1.7 times greater than the rate of nonsmokers."
Studies have also found a very strong association between smoking and a type of pustular psoriasis called palmoplantar pustulosis.
How does it affect the body?
Studies of how smoking might affect psoriasis on a biological level are complicated by the thousands of ingredients in cigarette smoke. Dr. Naldi points to nicotine as a possible culprit in altering the immune system and possibly skin cell growth, as well as directly affecting skin inflammation.
Smoking and alcohol may also be associated with the same psychosocial factors that may drive psoriasis, such as stress, worry and poor coping skills.
How does lifestyle affect risk?
A 2000 study examined the effects of various lifestyle practices on psoriasis. The researchers first found that alcohol use and smoking have negative effects on psoriasis (as did emotional stress, obesity and lack of exercise).
Then the researchers split the study participants into two groups, based on whether they had ever had remissions or a time when the disease had disappeared completely.
The results were dramatic: 78 percent of people who had experienced remissions were nonsmokers, and only 22 percent were smokers. But of those who never experienced a remission, 66 percent were smokers, and only 34 percent were nonsmokers.
Alcohol appears to affect psoriasis in men more strongly than in women. One study found that heavy drinking actually lowered treatment response in men. Other studies have shown that men with psoriasis drink more than men without, that there is a significantly higher incidence of psoriasis in alcoholics, and that abstinence can improve the severity of the disease.
Dr. Naldi confirms that "data concerning alcohol consumption are less clear-cut. It seems that only young men who are heavy drinkers are at a higher risk for psoriasis, but other studies have shown that drinking alcohol has a negative effect on clinical response to treatment and on the likelihood of remission."
In addition, it should be noted that alcohol can have dangerous side effects when combined with certain psoriasis medications, such as methotrexate or acitretin (brand name Soriatane) in women of child-bearing potential.
What about psoriatic arthritis?
There is very little data available about the effects of alcohol or smoking on psoriatic arthritis. One small study published in 1996 looked at the effects of smoking on ankylosing spondylitis (AS), which is a type of arthritis of the spine and neck that affects some people with psoriatic arthritis.
After looking at clinical tests, X-rays and laboratory measurements, the authors concluded that smoking was associated with poor long-term outcomes in AS patients.
However, according to Dafna Gladman, M.D., F.R.C.P.C., professor of medicine at the University of Toronto, there simply isn't any data yet to confirm if people with psoriatic arthritis might experience similar negative effects from smoking or alcohol.
Dr. Gladman does believe, however, that there may be more evidence to indicate that smoking and alcohol may lower treatment response of a person with psoriatic arthritis.
More research needed
Ongoing studies in the United States are currently pursuing these links. The Utah Psoriasis Initiative led by Gerald Krueger, M.D., at the University of Utah, is a long-term study of people with psoriasis.
Preliminary analysis of their data suggests that smoking has a negative impact on psoriasis and supports "dermatologist-initiated counseling on smoking cessation to improve their patients' skin disease as well as their general health."
"It's a fascinating linkage," says Dr. Krueger. "If the disease is triggered by smoking, can we get the disease back in the can by quitting? We just don't know yet. However, I tell people that if you need another reason to quit, you've got one."
The bottom line
- If you don't smoke, don't start, especially if you are a woman—you have an even higher risk of developing psoriasis than men.
- If you do smoke, consider stopping—you may have a higher likelihood of remission.
- If you drink, do it in moderation—heavy drinking may trigger psoriasis, interfere with your response to treatment and prevent remissions.
- If you are on certain medications, do NOT drink—alcohol can lead to serious side effects for patients using methotrexate; women of child-bearing potential also should not drink if they have to take Soriatane.
- Focus on positive, healthy ways to cope with stress and anxiety—try meditation, counseling, adequate sleep, healthy diet and exercise.
- Be sure your children know of the additional risk if they smoke or drink heavily—Dr. Naldi says smokers with a family history of psoriasis increase their risk as much as nine times.