Researchers are learning more about the pathophysiology of rosacea, including the many ways in which the human microbiome might affect the skin. Studies uncovering potential roles of Demodex mites and more in rosacea could result in new options for treatment, but big questions remain.
“We understand that this is an inflammatory disease and involves abnormalities in the immune system,” says Linda Stein Gold, M.D., director of dermatology clinical research at Henry Ford Hospital, Detroit, Mich.
Mites in the microbiome
Demodex mites normally exist in the human microbiome but the numbers of these mites appear to be more than four-fold on rosacea sufferers’ facial skin, according to Frank Powell, M.D., consultant dermatologist at Mater Misericordiae Hospital in Dublin and former president of the European Academy of Dermatology and Venereology. Dr. Powell was among the roundtable experts on the clinical implications of Demodex in rosacea during the American Academy of Dermatology’s March 2015 annual meeting in San Francisco.
“Researchers have more recently discovered that while Demodex folliculorum and D. brevis live in the hair follicles and sebaceous glands of the facial skin, D. folliculorum is also found in the meibomian glands of ocular rosacea patients,” Dr. Powell said in a July 30, 2015 National Rosacea Society press release. “In the mites’ brief life span of 14 days, they live and reproduce in the pilosebaceous units, subsisting on sebum and cellular contents, and emerge from the follicles primarily at night.”
But how this all plays out for individual rosacea patients remains unclear.