Improper use of oral antibiotics, including long-term use over months to years, has resulted in resistant bacteria that are posing a serious health threat, according to Dr. Theodore Rosen, professor of dermatology at Baylor College of Medicine, at a recent meeting of the American Academy of Dermatology. He also noted that alternative options are available that can minimize this risk.

"We are being bombarded every year by increasingly resistant bacteria," Dr. Rosen said. "Some of these are relatively trivial, some are really bad -- like MRSA (methicillin-resistant Staphylococcus aureus) -- and some are wreaking havoc."

Bacteria may develop resistance through exposure to an antibiotic over a long period of time, he explained, including through food animals, such as cattle, that are routinely given antibiotics, as well as patients prescribed the drugs long-term.

In addition, bacteria may become resistant to multiple drugs and may spread their immunity among other bacterial strains, he said, resulting in unresponsiveness to treatment for such potentially harmful bacteria as the widespread Escherichia coli, linked to urinary tract infections and food poisoning, and even Yersinia pestis, the causative organism of bubonic plague.

According to the World Health Organization, there were 9.5 million new tuberculosis cases and nearly 2 million deaths in 2008 -- and about 150,000 of the fatalities were due to multi-drug-resistant strains.

Dr. Rosen recommended that the use of oral antibiotics in treating rosacea be minimized by using a low-dose, controlled-release oral therapy to reduce the potential for bacterial resistance as well as to avoid side effects associated with long-term use. He noted that the potential for bacterial resistance is minimized because the lower dosage treats the inflammation of rosacea with no demonstrated antibacterial effects.

"Given that rosacea is a chronic condition requiring long-term therapy, this as well as topical therapy are important treatment options for eliminating the risk of bacterial resistance," he said.

In treating mild to moderate rosacea, doctors often prescribe oral and topical therapy to bring the condition under immediate control, followed by long-term medical therapy to maintain remission. When appropriate, higher doses of oral antibiotics may be prescribed, and other drugs may be used for patients who are unresponsive to conventional treatments.