Clinical presentations and classification of rosacea.

Rosacea is a chronic skin disease affecting up to 10% of the population in some European countries. Rosacea manifests as various combinations of characteristic signs and symptoms in a centrofacial distribution. At present, there is no consensus about the definition or classification of the clinical patterns of rosacea. Initially, four stages were differentiated (pre-rosacea then stages I through III), with several variants (e.g., persistent erythema and edema, rosacea conglobata, and rosacea fulminans). The National Rosacea Society (NRS) in the USA has classified rosacea into four subtypes (erythematotelangiectatic, papulopustular, phymatous, and ocular) and one variant (lupoid or granulomatous rosacea). This classification scheme does not mention progression from one type to another and makes no reference to pathophysiological considerations. It uses major and minor diagnostic criteria based on the physical findings and symptoms. The NRS has also developed criteria for grading disease severity. The classification of rosacea into stages or subtypes, without considering the possibility of progression from one to another, will probably remain controversial until additional knowledge on the pathophysiology of rosacea is obtained.