acne vs acne rosacea

acne and acne rosacea both are nouns.

Word	Noun	Adjective	Verb	Adverb
acne	Yes	No	No	No
acne rosacea	Yes	No	No	No

As nouns, acne rosacea is a hyponym of acne; that is, acne rosacea is a word with a more specific, narrower meaning than acne:

acne: an inflammatory disease involving the sebaceous glands of the skin; characterized by papules or pustules or comedones
acne rosacea: a skin disease of adults (more often women) in which blood vessels of the face enlarge resulting in a flushed appearance

Other hyponyms of acne include rosacea, acne vulgaris, hickey, pimple, zit.

acne (noun)	acne rosacea (noun)
an inflammatory disease involving the sebaceous glands of the skin; characterized by papules or pustules or comedones	a skin disease of adults (more often women) in which blood vessels of the face enlarge resulting in a flushed appearance