。
Do you have any drug allergies?
Literal
Medicine [to-に] allergy [subj-が] exist-[polite-Q-ますか].
A staple medical intake question. Note the structure: the thing one is allergic to is marked with に, and アレルギーがある is a stative existence construction meaning 'to have an allergy.' アレルギー is a loanword — from German 'Allergie' via mid-20th-century medical vocabulary, not English.