Research suggests rosacea subtypes may be different conditions

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An article in Dermatology Times, Research suggests rosacea subtypes may be different conditions, by John Jesitus, reports on the what Frank C. Powell, M.D., said at the 2012 annual meeting of the American Academy of Dermatology.

Highlights worth noting:

Powell in discussing how neurogenic rosacea stems from the combination of a genetic predisposition and exogenous factors such as light, heat or microbes says, "These factors initiate a neurovascular response, with vasodilatation, peptide release and central appreciation of pain. This is an interesting concept."

With regard to the controversy on classifying rosacea into subtypes he suggests the possibility that these subtypes may possibly be "different conditions."

As for causes of rosacea, Powell says research has discredited potential culprits ranging from menopause to diet and alcohol.

Powell then discusses demodectic rosacea, elevated cathelicidin, kallikrein (KLK) five levels, toll-like receptor (TLR)-2 which activates KLK5, and states, [As a result of the above advances,] "It is generally accepted that the inflammation in papulopustular rosacea is folliculocentric," Dr. Powell says. "This is an important change in our concept of the pathogenesis of this disease. Up to now, rosacea was thought to be a vascular disease predominantly."

Although the cause of rosacea remains unclear, "We know that surface lipids are different in rosacea, and that the innate immune response is altered," Dr. Powell says. "We are now inclined to believe that the pilosebaceous unit is central to papulopustular rosacea pathogenesis. And we must consider whether Demodex-related bacteria have a role in rosacea colonization."

Another group investigated isotretinoin — 20 mg daily for four months, followed by six months' tapering — for resistant or relapsing papulopustular rosacea. "They found that in the inflammatory lesions, erythema and sebum levels were significantly decreased from baseline (Uslu M, Savk E, Karaman G, Sendur N. Acta Derm Venereol. 2012;92(1):73-77,)" he says. Within a median follow-up of 11 months, however, 45 percent of the isotretinoin patients relapsed.