Treatment options: What works?
One treatment that is clinically effective in studies is topical ivermectin, an FDA approved for rosacea treatment and an antiparasitic drug.
“We know that [ivermectin] has some activity against Demodex. It’s used commonly in veterinary medicine to treat Demodex,” Dr. Stein Gold says. “But it hasn’t been studied extensively in humans. And we haven’t really evaluated to a real scientific degree the effect of Demodex on different treatment modalities.”
Ivermectin also has anti-inflammatory properties, which affect cellular and the humoral immune responses and has been shown to downregulate some proinflammatory cytokines, according to Dr. Stein Gold.
“Some people have treated Demodex by using oral ivermectin. But I haven’t really seen any good clinical trials that have evaluated that. It’s more case reports that people talk about,” Dr. Stein Gold says.
On the horizon is oxymetazoline2, which is in clinical trials and, like topical brimonidine, targets rosacea’s erythema.
If these are potential “in” treatments for rosacea, one that’s out is using a full-strength oral doxycycline at high doses for prolonged periods to treat the skin disease. High doses are unnecessary, according to Dr. Stein Gold.
“We know that the role of doxycycline in rosacea is really used for anti-inflammatory properties and, that, by using anti-inflammatory doses instead of using high dose doxycycline, we actually are able to control rosacea very well. By keeping those low doses, we don’t have to worry about the development of resistance,” Dr. Stein Gold says.
Low dose oral doxycycline is the answer, according to Dr. Thiboutot.
“We know more about doxycycline because doxycycline has been shown to affect matrix metalloproteinases (MMPs) enzymes that may play a role in rosacea with regard to cathelicidin activation,” Dr. Thiboutot says. “So, the treatments are: low-dose oral doxycycline, topical metronidazole, topical azelaic acid and topical ivermectin.”