Rash, like hives or herpes for example (3-6)
I believe the answer is:
hot-headed
'rash' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for hot-headed that I've seen before include "Impetuous, quick-tempered" , "Impulsive" , "Impetuous, rash" .)