Skin & Eye Watch

Long-Term Use of Antibiotics to Treat Acne Not Linked to Increased Bacterial Resistance

New research is challenging the notion that prolonged use of the tetracycline antibiotics commonly used to treat acne is linked to increased bacterial resistance. According to findings from a study that will appear in the August issue of Archives of Dermatology, tetracycline antibiotic use is, in fact, associated with a reduced prevalence of Staphylococcus aureus bacteria.

Matthew Fanelli, MD, and colleagues at the University of Pennsylvania School of Medicine conducted a survey of patients treated for acne to determine the frequency of S aureus colonization and to compare the susceptibility patterns between patients who are using antibiotics and those who are not. Thirty-six of the 83 patients in the study were colonized with S aureus; of those, 2 (6%) had methicillinresistant S aureus, 20 (56%) had S aureus solely in their throats, 9 (25%) had S aureus solely in their noses, and 7 (19%) had S aureus in both their noses and throats.

“Long-term use of antibiotics decreased the prevalence of S aureus colonization by nearly 70%,” the authors wrote, adding that a decreased rate of colonization was noted with the use of both oral and topical antibiotics. Fewer than 10% of the isolates of S aureus were resistant to tetracyclines, the antibiotic family most commonly used to treat acne, and resistance to erythromycin and clindamycin was mostly prevalent among the isolates and was noted in both patients who did and did not use antibiotics. PT

Topical Corticosteroids Safe for Children with Eczema

The results of a study published in the March/April issue of Pediatric Dermatology indicate that routine, long-term use of topical corticosteroids (TCS) for treating children with eczema is not associated with any significant negative side effects.

Many parents and health care providers, including pharmacists, have concerns about the safety of topical corticosteroids, which can affect usage and result in poor management of the condition. A common fear, according to the study, is that the ointments will cause thinning of the child’s skin.

In the study, a team led by Gayle Fischer, MBBS, FACD, of the University of Sydney, observed 70 children who were treated with enough TCS to keep their skin virtually free of eczema, and 22 who did not use the medication. They examined the children for any signs of corticosteroid-related side effects, and found that there were no differences between the children receiving the medication and those in the control group.

“Our results show that normal routine use of TCS does not cause skin thinning, and parents should be reassured,” said Fischer. “We hope that our work will give them the confidence to use TCS safely and effectively.”

Vitamin D Intake Can Lower Risk of Age-Related Macular Degeneration

High levels of vitamin D in the bloodstream appear to be associated with a decreased risk of developing early age-related macular degeneration (AMD) among women younger than 75 years, according to a report published in the April issue of Archives of Ophthalmology.

Amy E. Millen, PhD, and colleagues from the University at Buffalo, New York, examined data from 1313 women to determine whether serum 25(OH)D levels in the blood were linked to early AMD, a disease that affects approximately 9% of Americans 40 years and older. Serum 25(OH)D is the preferred biomarker for vitamin D status because it reflects vitamin D exposure from both oral sources and sunlight, according to the study’s authors.

After Dr. Millen and colleagues adjusted for age and other known risk factors for AMD, no significant relationship was found between vitamin D status and early or advanced AMD.

In women younger than 75 years, higher levels of serum 25(OH)D were associated with a significantly decreased risk of early AMD. However, in women 75 years and older, higher levels were associated with a borderline statistically significant increased risk. In women younger than 75 years, intake of vitamin D from foods and supplements was associated with decreased risk of developing early AMD. Women who consumed the most vitamin D had a 59% lower chance of developing early AMD compared with women who consumed the least vitamin D. The top food sources of vitamin D in the sample were milk, fish, fortified margarine, and fortified cereal. No relationship was observed using self-reported time spent in direct sunlight.

“This is the second study to present an association between AMD status and 25(OH)D, and our data support the previous observation that vitamin D status may potentially protect against development of AMD,” the authors concluded.