Origin of "A pox/curse on both their houses"
Solution 1:
Pox is an alternate spelling of pocks, which has come to us directly from Old English. Pocks are the pustules of some diseases, notably small pox and syphilis, and the word became attached as the name of the disease as well. The OED finds a usage from 1530 in which the pocks is called a punishment from God, so to call down a pox on a house is to wish the punishing calamity of a deadly disease on the family.