Azelaic acid is one of the more fascinating drugs in dermatology. It is a dicarboxylic acid, (two carbon-oxygen groups) which is interestingly produced by the same yeast organism ( Malassezia Furfur) that causes "sun spots", the all too common Tinea Versicolor. It can be found in wheat, rye, and barley.
Like a college student who keeps switching majors, this is a drug which has long been seeking its niche in the dermatology armamentarium. At first it was to be a drug for acne, for which it was approved. Its use in acne is only mildly praised by most of my dermatology colleagues. ( Except in pregnancy where it is one of our few safe options). It then seemed to become popular as a bleaching agent, especially for melasma. Though off label for this indication, it does work, but not to an overwhelmingly impressive degree.
Finally, it seems to have found its role in the treatment of Rosaea. Some very recent work by the outstanding researcher Dr. Richard Gallo, the chairman of the dermatology department at the University of California, San Diego underscores this. His study showed that Azelaic Acid inhibits the Toll-like Receptor 2 ( has nothing to do with tolls like such as in a toll road, but is actually from the German word Toll which roughly means "wow" according to my friend Dr. Helmut Tilch), kallikrein 5, cAMP ( cyclic adenosine monophosphate, the favorite of biochem teachers everywhere), pathway. Many dermatologists, including myself, regard this pathway activation as the cause of Rosacea.
This action downregulates cathelicidins, normally a crack part of the skin's defense mechanisms, Cathelicidins are at a much higher level in the skin of those with Rosacea. It is the cathelicidins that cause the redness, edema, and irritation characteristic of this blushing disorder. Azelaic acid ( in Finacea), can specifically target those proteins that spark the signs and symptoms of rosacea.
One interesting side note in Dr. Gallo's study was that lower levels of azelaic acid (AZA) seem to work better than higher levels. Most dermatologists feel that finacea gel (15% AZA) is superior to Azelex cream ( 20% AZA). I had always thought the rational for this was that gels penetrate better than creams. However, it may be that the lower concentration found in Finacea, may, per se, be more efficacious.