chronic eczema vs eczema

chronic eczema and eczema both are nouns.

Word	Noun	Adjective	Verb	Adverb
chronic eczema	Yes	No	No	No
eczema	Yes	No	No	No

As nouns, eczema is a hypernym of chronic eczema; that is, eczema is a word with a broader meaning than chronic eczema:

chronic eczema: eczema characterized by thickening of the skin with accentuated skin lines
eczema: generic term for inflammatory conditions of the skin; particularly with vesiculation in the acute stages

chronic eczema (noun)	eczema (noun)
eczema characterized by thickening of the skin with accentuated skin lines	generic term for inflammatory conditions of the skin; particularly with vesiculation in the acute stages