Infectious diseases: A never-ending battle

Las Vegas

- The evolving nature of infectious diseases that attack the skin requires dermatologists to maintain constant vigilance, an expert says.

In diagnosing and treating infectious diseases, says Theodore Rosen, M.D., professor, Department of Dermatology, Baylor College of Medicine, "It's what you learn after you know it all that really counts." Just when one believes one has mastered every unpronounceable infection and treatment for it, he explains, experts change the culprit organism's name, the organism learns new pathologic tricks or new organisms arise.

Between 1997 and 2007, Dr. Rosen says, the number of medical visits for abscesses has grown 88 percent, with presumptive methicillin-resistant Staphylococcus aureus (MRSA) rising from seven percent to 28 percent of these cases.

"In my own locale," he says, "more than 70 percent of all staph infections are MRSA." Furthermore, he says the appearance of community-acquired MRSA is no longer news. In fact, as the critical distinctions between these two entities continue to blur, it's more important to recognize local resistance and susceptibility patterns than differentiating between community and hospital sources.

Diagnostically, Dr. Rosen cautions that MRSA won't necessarily look like a boil. Current guidelines recommend using antibiotics only in limited instances such as for large lesions of those with associated cellulitis.

However, he says, the latest studies contradict these recommendations."In fact," he says, "patients respond better and recover more quickly if, along with incision and drainage, they’re placed on appropriate antibiotics to which the organism is susceptible." In this regard, he says doxycycline probably remains the go-to drug for most dermatologists, but MRSA's potential for tetracycline resistance makes minocycline perhaps a more rational choice.

Additionally, dermatologists must consider new sources of infectious skin disease, Dr. Rosen tells Dermatology Times.

"There's a new organism coming back from Iraq called Acinetobacter baumannii. It can cause skin and soft tissue infection following traumatic war injury," particularly from improvised explosive devices, he says.

"Originally, this was thought to be implanted from the ground at the time of the wound," but researchers now believe the organism originates in military medical facilities, he says.

Somewhat similarly, the incidence of leishmaniasis in returning soldiers is rising.

"Dermatologists need to realize that dengue fever is not just something we learn about in medical school," Dr. Rosen says.

Just as the number of dengue infections acquired abroad is increasing, it’s "not too far-fetched" that physicians will begin seeing cases originating in and spreading throughout the United States. DT

Disclosures: Dr. Rosen serves on speakers' bureaus for GlaxoSmithKline and Graceway.