1876, short for acne rosacea (1833), from fem. of Latin rosaceus "rose-colored" (see rose (n.1)).
rosacea ro·sa·ce·a (rō-zā'shē-ə)
n.
A chronic dermatitis of the face, especially of the nose and cheeks, characterized by a red or rosy coloration with deep-seated papules and pustules and caused by dilation of capillaries. Also called acne erythematosa, acne rosacea.