A new standard classification and pathophysiology of rosacea was recently published in the Journal of the American Academy of Dermatology based on the substantial advances in the understanding of rosacea gained through scientific investigations over the last 15 years.

“There has been an explosion of research on rosacea since the first standard classification system appeared in 2002, and that has resulted in a much deeper scientific understanding of this common but once little-known disorder,” said Dr. Richard Gallo, chairman of dermatology, University of California-San Diego and chairman of the NRS consensus committee and review panel of 28 rosacea experts worldwide.

Although the cause of rosacea remains unknown, recent studies have shown that the initial redness is likely to be the start of an inflammatory continuum initiated by a combination of neurovascular dysregulation and the innate immune system. While the original classification system designated the most common groupings of primary and secondary features as subtypes, the committee noted that it now seems appropriate to focus on the individual characteristics, called phenotypes, that may result from this disease process.

According to the new system, a diagnosis of rosacea may be considered in the presence of at least one diagnostic sign — either persistent redness of the central facial skin or, less commonly, thickened skin in the central face (known as phymatous changes, often on the nose). Two or more major signs, including bumps and pimples, flushing, visible blood vessels and eye irritation may also indicate rosacea. Secondary signs and symptoms, such as burning or stinging, swelling and dry appearance, may also develop but are not diagnostic. Physicians must rule out other possible causes of rosacea-like symptoms — such as lupus, steroid-induced rosacea or seborrheic dermatitis — before confirming the diagnosis.

“Although rosacea’s various phenotypes may appear in different combinations at different times, research suggests that all are manifestations of the same underlying disease process, and that rosacea may progress not only in severity but to include additional phenotypes,” Dr. Gallo said.The committee also acknowledged the psychosocial effects of rosacea, noting that multiple patient surveys have documented rosacea’s substantial adverse impact on emotional, social and occupational well-being.

Fortunately, a growing number of medical therapies are now available that can be tailored to treat the signs and symptoms of each individual case, with potential to substantially reduce the impact of rosacea on people’s lives.