Our most widely-read post on this blog is about a rash I had around my mouth and how I discovered what triggered it and how I finally healed it. That particular rash was the result of an allergic reaction to propolis. But not all rashes near the mouth or on the face are caused by allergic contact dermatitis. Sometimes they are the result of a condition called perioral dermatitis. Differentiation of mouth/face rashes is important because the treatments for allergic contact dermatitis, acne, rosacea, or eczema can make perioral dermatitis worse.