skin disorder vs disease

skin disorder and disease both are nouns.

Word	Noun	Adjective	Verb	Adverb
skin disorder	Yes	No	No	No
disease	Yes	No	No	No

As nouns, disease is a hypernym of skin disorder; that is, disease is a word with a broader meaning than skin disorder:

skin disorder (noun)	disease (noun)
a disease affecting the skin	an impairment of health or a condition of abnormal functioning