-- Using antibiotics to treat rosacea -- a regimen that has no basis in evidence but a long history in daily clinical practice -- has contributed to antibiotic resistance, according to a review of the latest evidence.
The primary suspects in this case are the tetracyclines, particularly doxycycline, explained Hilary E. Baldwin, M.D., an associate professor and vice-chair of the department of dermatology at SUNYDownstate Medical Center in New York.
And, in a surprising finding, resistance to doxycycline can occur in a few days, with resistant bacteria in abundance after just seven days of treatment with 100 mg doxycyline daily, she said.
Dr. Baldwin reviewed rosacea treatments during a presentation at the Skin Disease Education Foundation Hawaii Dermatology Seminar.
She said that antibiotics became a standard rosacea treatment because of the mistaken belief that "the etiology of rosacea was bacterial. But the best current evidence is that microbes are not involved."
Importantly, she said, "no antibiotic is FDA approved for treatment of rosacea."
Yet, antibiotics continue to be a standard course because they "appear to be effective for treatment of papulopustular rosacea," she said.
But tetracyclines work, Dr. Baldwin explained, not because of their antibiotic properties but because "they have anti-inflammatory activity."
Specifically, tetracyclines are involved in downregulation of proinflammatory cytokines, inhibition of angiogenesis, inhibition of neutrophil chemotaxis, inhibition of nitric oxide activity, and suppression of neutrophil-derived production of reactive oxygen species -- all of which helps them take the red out of rosacea.
And if one reduces the doxycycline dose to 50 mg or less a day, "you have an anti-inflammatory dose, not an antibiotic dose."
But she warned that "giving 100 mg every other day, is not an anti-inflammatory dose."
The 100 mg every other day actually promotes antibiotic resistance because it is starting and stopping an antibiotic regimen.
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Primary source: Skin Disease Education Foundation Hawaii Dermatology Seminar Source reference: Baldwin HE "Everything's coming up rosey" SDEF 2009. |
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