Advertisement

Ivermectin Mite Work

April 4, 2014

Ivermectin Mite Work

  1. Mark V. Dahl, MD

Topical ivermectin 1% cream was effective for clearing papulopustular rosacea, and its antiparasitic action may be why.

  1. Mark V. Dahl, MD

Studies of papulopustular rosacea patients show increased incidence of demodex mite infestation, and when present, mite density in the follicles is increased compared with controls. The Demodex folliculorum mite lives head-down in the follicle, where it feeds on sebum, shed skin cells, and other co-inhabitants of the infested follicle. A causal relationship of demodex to papules, pustules, and other skin manifestations of rosacea has not been proved. Ivermectin kills some parasites, so investigators studied whether topical ivermectin might reduce rosacea papules and pustules in two phase III, multicenter, randomized, double-blind, parallel-group, vehicle-controlled studies with identical protocols.

A total of 683 patients with moderate-to-severe facial rosacea and 15 to 70 inflammatory papules and pustules were randomized to apply either ivermectin cream 1% or vehicle cream to the face at bedtime for 12 weeks. Results were similar in both trials. About 40% of ivermectin cream users were “clear or almost clear” after 12 weeks, versus about 15% of users of vehicle alone (P<0.001). By week 12, the median percentage decrease from baseline in the number of inflammatory papules was greater with ivermectin (76% and 75%) than with vehicle (50% in both studies; P<0.001). The percentage of patients who self-rated their improvement as excellent or good was greater with ivermectin than with vehicle (69% and 66% vs. 39% and 34%, respectively; P<0.001). There were no severe adverse effects.

Comment

Ivermectin 1% cream seems to be safe and effective for papulopustular rosacea. The study was not designed to correlate efficacy with mite infestation or density, so we do not know if all responders had infestations before treatment. Ivermectin's mechanism of action suggests that demodex mites might cause papules and pustules, but ivermectin has anti-inflammatory actions as well as antiparasitic ones, down-regulating both interleukin-1b and tumor necrosis factor-α.

  • Disclosures for Mark V. Dahl, MD at time of publication Consultant / Advisory board Genentech; Makucell, Inc.; Mayo Clinic Equity Elorac, Inc.; Johnson & Johnson; Pfizer Speaker's bureau Los Angeles Dermatological Society; University of Southern California Editorial boards UpToDate

Citation(s):

Reader Comments (1)

JEFFERSON DICKEY Physician, Internal Medicine

Why was the vehicle so effective?

Your Comment

(will not be published)

Filtered HTML

  • Allowed HTML tags: <a> <em> <strong> <cite> <blockquote> <code> <ul> <ol> <li> <dl> <dt> <dd>
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Do you have any conflict of interest to disclose?
CAPTCHA
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Image CAPTCHA
Enter the characters shown in the image.

Vertical Tabs

* Required

Reader comments are intended to encourage lively discussion of clinical topics with your peers in the medical community. We ask that you keep your remarks to a reasonable length, and we reserve the right to withhold publication of remarks that do not meet this standard.

PRIVACY: We will not use your email address, submitted for a comment, for any other purpose nor sell, rent, or share your e-mail address with any third parties. Please see our Privacy Policy.

Advertisement
Advertisement
Advertisement