While rosacea has sometimes been described as affecting adults between the ages of 30 and 50, in actuality it may be just as common and even more severe after age 50.

"Rosacea not only can develop at any age, but it is a chronic condition that seldom goes away by itself, and therefore its prevalence may tend to increase as populations advance in age," said Dr. John Wolf, chairman of dermatology, Baylor College of Medicine. "Moreover, because rosacea tends to become progressively more severe without medical help, the symptoms are often especially intrusive in older patients who have delayed proper diagnosis and treatment over the years."

Rosacea usually first strikes when people are in their 30s and 40s as well as in their 50s and 60s, as a redness on the cheeks, nose, chin or forehead that comes and goes. As the disease progresses, the redness becomes ruddier and more permanent, and tiny dilated blood vessels may become visible.

Left untreated, acne-like bumps and pimples often develop and, in advanced cases, further inflammation develops and the nose may become bumpy, red and enlarged from excess tissue. This is the condition that gave the late comedian W.C. Fields his trademark bulbous nose. In some individuals, rosacea also causes the eyes to become watery, red and irritated as it increases in severity.

In a survey of more than 2,000 rosacea patients by the National Rosacea Society, 44 percent reported that their symptoms first appeared in their 30s and 40s, while 43 percent said they first noticed rosacea symptoms after age 50. Only 13 percent said they first developed rosacea before age 30.

For 26 percent of the survey respondents, early symptoms advanced within a few months to middle-stage rosacea, in which the redness becomes more severe and persistent, sometimes with tiny visible blood vessels and often with the appearance of bumps and pimples. For 23 percent of the respondents, early symptoms advanced to middle stage within a year, and for 46 percent the disorder took a number of years to progress to this stage.

The survey indicated that 45 percent had middle-stage rosacea when they sought medical diagnosis and treatment, while for 41 percent the early signs were enough to prompt them to consult a dermatologist. However, 11 percent said they did not seek diagnosis and treatment until their condition reached advanced stages.