I found this information.
Perioral dermatitis is an acne-like condition of unknown cause. Some possible causes are the use of topical corticosteroid creams, cosmetic products, oral contraceptives, fluoride and anti-tartar ingredients in dental products, and it tends to occur in those prone to eczema.
I learned that it affects mostly women, but is it because they use more of cosmetic products? Steroid is a trigger, since I know from my own experience that it affects production of platelets.
Mikulas