Sometimes you can overdo a good thing.
Like washing your hands too much with antibacterial soaps.
In fact, researchers say, people with sensitive hands -- and even those with normal skin -- can actually increase the risk of spreading disease by using the soaps too often.
"The antibacterial products contain some of the harshest chemicals, as far as the skin is concerned," said Dr. Marianne O'Donoghue, associate professor of dermatology at Rush-Presbyterian-St. Luke's Medical Center in Chicago.
Those chemicals can strip away protective fats and oils on the skin's surface, leading to development of cracks in the skin and creating an environment where microorganisms can invade and cause infection.
Although scientists have warned that overuse of antibacterial products might result in the creation of drug-resistant "superbugs," O'Donoghue said she is more concerned about the real-world problems of dermatitis and eczema.
"There is nothing quite as good for spreading bacteria as hand eczema," O'Donoghue said at the scientific meeting of the American Academy of Dermatology in August. What happens, she explained, is that a person who is sensitive to the antibacterials, or a person over-washes, develops eczema. Then when the person touches a surface, the microbes are deposited there and can infect others.
O'Donoghue said that because the products often come equipped with a handy pump dispenser, this increases the potential for overuse. "People just love that little pump," she said.
"I've have patients who have developed hand eczema by overuse of these products," said Lt. Cmdr. William Baugh, chief of dermatology at the Beaufort (S.C.) Naval Hospital. "They think they are being good citizens by washing their hands all the time. I asked one man (who used antibacterial soaps) with a particularly bad case of eczema how often he washed his hands. He said, 'About, 20 times a day.' "
In order to kill bacteria, the soap products contain detergent chemicals that strip away defenses from the pathogen, Baugh explained. But in defeating the bug, the products also wreak havoc with the skin on the hands.
"They literally strip away fatty acids, moisture and amino acid from the skin," O'Donoghue said, "They increase dryness and roughness, and disturb the healthy growth process."
Baugh tells his patients to use non-detergent products that contain emollients that replace oils in the hands.
One problem people might have with finding the right product is that antibacterial soap products are ubiquitous. A recent survey found that nearly half of 1,100 liquid and solid soaps contain antibacterial agents.
"No one has ever been able to prove that using antibacterial soaps meant that anyone was better off than those using standard soap," said Dr. Eli Perencevich, a research fellow in infectious diseases at Beth Israel Deaconess Medical Center in Boston, who performed the survey.
"However, there are studies that suggest use of such products kill off the sensitive bacteria, leaving hardier bacteria, such as E. Coli and staphylococcus aureus, which could be detrimental to health. The fear is that this process will result in bacteria that live longer," he said.
That fear may be misplaced, contend industry representatives.
"While some studies have shown that antibacterial ingredients may promote resistant bacteria, these studies have been done under controlled laboratory conditions that do not reflect what happens to bacteria that consumers encounter in the real world," said Dr. Jerry McEwen, vice president for science at the Cosmetic, Toiletry and Fragrance Association.
But, O'Donoghue said, what does happen is that in the real world, people who use the products can end up with serious skin diseases that need expert help to correct.