Rosacea (IPA: [ɹəʊ.ˈzeɪ.ʃə]) is a common but often misunderstood condition that is estimated to affect over 45 million people worldwide. It affects fair-skinned people of mostly north-western European descent, and has been nicknamed the 'curse of the Celts' by some in Ireland. It begins as erythema (flushing and redness) on the central face and across the cheeks, nose, or forehead but can also less commonly affect the neck and chest. As rosacea progresses, other symptoms can develop such as semi-permanent erythema, telangiectasia (dilation of superficial blood vessels on the face), red domed papules (small bumps) and pustules, red gritty eyes, burning and stinging sensations, and in some advanced cases, a red lobulated nose (rhinophyma). The disorder can be confused and co-exist with acne vulgaris and/or seborrheic dermatitis. Rosacea affects both sexes, but is almost three times more common in women, and has a peak age of onset between 30 and 60. The presence of rash on the scalp or ears suggests a different or co-exisitng diagnosis, as rosacea is primarily a facial diagnosis.

Source Wikipedia  http://en.wikipedia.org/wiki/Acne_rosacea