Similar to acne, rosacea has a significant economic cost and psychosocial impact. Because the features of rosacea are so visible, people with rosacea are often distressed and embarrassed about their appearance and may exhibit low self-esteem. Negative effects on psychological well-being may extend to social and business relationships.
The cause of rosacea is unknown and there is no cure. This vascular disorder involves enlargement of the blood vessels just under the skin, which may become visible spidery veins (telangiectasis) and oil glands. Long-term rosacea may produce a permanently enlarged and nodular nose (rhinophyma, nasal bumps), the result of recurrent facial swelling that leads to overgrowth of tissue (fibroplasia).
Early treatments for rosacea ran the gamut from blood-letting in the arm, forehead and nose, to applying leeches on affected areas. The use of salves containing such ingredients as mercury, sulphur and bull's blood as treatment was first referred to in the 16th century.
A written reference to "acne rosacea" appeared in an English medical text by Dr Thomas Bateman in 1812, who noted, "The perfect cure of acne rosacea is, in fact, never accomplished." Other 19th century references commonly listed rosacea among the different forms of acne. During the 20th century, rosacea became increasingly recognized as a separate disease, requiring different therapy than acne. Effective medical treatment became available with the development of antibiotics after World War II and, in 1989, metronidazole was approved as the first topical therapy specifically for rosacea. Although the cause of rosacea is still unknown, it can usually be treated effectively with medication and avoidance of environmental and lifestyle factors that aggravate the condition in various individuals.
Rosacea has been noted in people as diverse as African Americans and Koreans, but it occurs most often in fair skinned people, particularly those who blush easily. Often called the "Curse of the Celts," rosacea is especially prevalent among individuals of Irish descent and also Scandinavian. Other ethnic categories with elevated rates of rosacea in the survey included Scottish, Welsh, Polish, Lithuanian and Balkan nationalities. There is also good indication that it is familial, for example in one survey 11 percent of adults with rosacea had children already diagnosed with the condition (prerosacea, characterized by frequent blushes or flushes that last a little longer than normal).