Medical experts speaking at a forum called "New Concepts in Rosacea" during the recent annual meeting of the American Academy of Dermatology discussed the potential vascular origins of rosacea, as well as features that rosacea and adolescent acne (acne vulgaris) -- a separate disorder that sometimes also appears in adults -- may have in common.

Dr. Jonathan Wilkin, chairman of the National Rosacea Society medical advisory board, reaffirmed his belief that rosacea appears to be primarily a vascular disorder, citing the changes that are most typically seen.

"Rosacea to me is vascular in that it seems to be related to flushing and persistent erythema (redness)," he said. "It most often begins with blushing and flushing, and that's the early clue."

He noted that edema (swelling) is often present and may be discovered by simply pressing a finger for several moments on the patient's face. Any presence of swelling will cause an indentation that is slow to recover its original shape. "Sun exposure damages the latticework that protects the lymphatic system in the face, leaving it more susceptible to such swelling," he explained.

Another suggestion that rosacea has vascular origins, according to Dr. Wilkin, is the fact that it can be reduced if the patient is able to control flushing or blushing -- for example, by avoiding environmental or lifestyle factors that trigger a flare-up in their particular case.

Dr. Albert Kligman, professor of dermatology at the University of Pennsylvania, believes there is overlap between adolescent acne and rosacea. He noted that there are common features, and that rosacea in individuals who had adolescent acne may be more difficult to treat.

Questioning of over 100 rosacea patients revealed approximately 20 percent had had a previous episode of acne. While rosacea is typically not associated with comedones (blackheads), a hallmark of acne, these individuals usually had shallow acne scars as well as microcomedones that were visible only under a microscope.

"It's true that there are no visible comedones in rosacea -- they are present, but they don't rise to a visible level," he said, noting that comedones may be a commonality between the two disorders.

Moreover, he said adolescent acne may often be accompanied by a tendency toward rosacea. When the child or adolescent becomes overheated after playing sports, there may be an episode of intense, persistent flushing, which may signal the disorder's likely future appearance in that individual.