Phymatous rosacea on a male patients forehead. Rosacea usually begins from a temporary flushing of the face, for example after drinking alcohol. It then develops into a permanent reddening of the skin. The phymatous subtype leads to thickening of the skin and enlarged pores. Its cause is usually unknown, but it can result from overuse of corticosteroid creams. Treatment is with a long-term course of antibiotics, but rosacea tends to recur for up to 10 years before disappearing completely.