Final answer:
The condition associated with ACEi use causing lip and tongue swelling is likely angioedema, which varies from hereditary angioedema that has a genetic basis and shows nonresponsive swelling to steroids.
Step-by-step explanation:
The condition that presents with lip and tongue swelling associated with angiotensin-converting enzyme inhibitor (ACEi) use is most likely angioedema. This is not to be confused with hereditary angioedema, which is a genetic disorder leading to similar symptoms due to compromised function of C1 inhibitor protein. Unlike reactions to ACEi, hereditary angioedema's swelling is often nonresponsive to steroids and may be misdiagnosed as an allergy. The swelling incidents related to hereditary angioedema can occur in different parts of the body, including the respiratory tract, gastrointestinal tract, and the muscles of the face or limbs.