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Posted on 07.02.03
Antibiotics Increase Risk for Acne Patients
By Mike Upchurch
Researchers at the University of Pennsylvania CERTs are finding more and more evidence of the growing problem of antibiotic resistance. In a study published in April’s issue of the Archives of Dermatology, Dr. David Margolis and his team found that patients with acne taking antibiotics are at increased risk for the presence of dangerous bacteria.
Patients with acne are usually otherwise healthy people who must take antibiotics for long periods of time. These patients made a perfect population for isolating the effects of antibiotic use on rates of resistance. Dr. Margolis and his fellow researchers studied 105 patients with acne. The investigators had no prior knowledge of their antibiotic use.
Of these 105, 42 had been using oral or topical antibiotics for at least 3 months. Those patients placed in the non-antibiotic group had to be at least 6 months removed from their last dose of antibiotics. Investigators tested all 105 for the presence of two common bacteria, Streptococcus pyogenes and Staphylococcus aureus. While just 10% of those not taking antibiotics had S. pyogenes in their throat cultures, one third of patients on antibiotics tested positive.
Of those 13 positive results, 85% proved resistant to at least 1 tetracycline antibiotic, one of the most commonly prescribed class of anti-infectives. Comparatively, only 20% of those not on antibiotics showed resistant strains of S. pyogenes.
There was no significant connection between antibiotic use and the development of resistant S. aureus. In fact, 29% of patients not on antibiotics tested positive for this particular strain of bacteria, compared with 22% of those taking antibiotics.
S. pyogenes is a potentially dangerous bacteria associated with diseases like scarlet fever and rheumatic fever. It is a common source of upper respiratory tract infections and particularly deep infections can lead to toxic shock syndrome or the destruction of the sheath of tissue around muscles, called necrotizing fasciitis.
While the proliferation of resistant bacteria on the skin of acne patients is well known, less is understood how it leads to resistant colonies in more distant locations like the throat. In Dr. Margolis’ study, patients using oral and topical antibiotics had similar rates of resistant bacterial infection. The authors speculate that this could be because of transfer of bacteria and/or topical antibiotic to the throat via fingers or eating utensils. Another explanation could be that even topical antibiotics can create conditions favorable for resistance throughout the body. Further testing will be necessary to pinpoint the reason.
While this study looked only at tetracycline resistance, previous research indicates that tetracycline-resistant strains of bacteria in the skin are frequently resistant to other agents such as penicillin or clindamycin. New studies will be needed to determine if this true for S. pyogenes in otherwise healthy patients, such as those in this study, and for bacterial colonizations in other parts of the body. This is another avenue of research the authors hope will be taken up with enthusiasm, given their initial findings.
Dr. Margolis was joined by lead author Ross Levy, Dr. Eric Huang, Dr. Daniel Rolling, and Dr. James Leyden. Arch Dermatol 2003; 139:467-471