smallpox, blister
疱 centers on a raised, fluid-filled swelling on the skin: a blister, or the disease smallpox which causes such blisters.
疱 combines 疒 (sickness) with 包, which likely contributes the sound ホウ and the idea of something wrapped or enclosed, like a blister.
The sickness enclosure 疒 wraps around 包 (wrap). Picture a sickness that wraps the skin in raised, fluid-filled blisters.
For ホウ, imagine a blister so large it looks like a small hoe (ホウ) growing on the skin. The hoe shape cues the reading while tying back to the blister meaning.
blister
shingles; herpes zoster
chickenpox; chicken pox; varicella
smallpox; variola
herpes simplex
pemphigus
acute generalized exanthematous pustulosis; AGEP
palmoplantar pustulosis
dyshidrosis; pompholyx; athlete's foot
herpes
smallpox demon; smallpox devil; deity to whom one prays for immunity to smallpox
pustule; pustula
empyesis; pustular eruption