丘疹[kyuushin] pimple
口辺単純疱疹[kouhentanjunhoushin] cold sore
湿疹[shisshin] eczema
発疹[hasshin] rash
風疹[fuushin] rubella

麻疹[hashika] measles
匐行疹[fukkoushin] ringworm
疱疹[houshin] herpes
蕁麻疹[jinmashin] hives
汗疹[asemo] prickly heat

隔靴掻痒[kakkasouyou] being frustrated because something is not quite as hoped (just as one cannot scratch an itch from outside a shoe)
歯痒い[hagayui] impatient
瘙痒[souyou] itch
痛痒[tsuuyou] pain and itching
痒い[kayui] itchy

痛し痒し[itashikayushi] delicate or ticklish situation
痒み[kayumi] itch
麻姑掻痒[makosouyou] things happening exactly as one pleases (wishes)
痒がる[kayugaru] to complain of itching
むず痒い[muzugayui] itchy