Trigeminal sensory neuropathy is an important finding, often indicative of
trauma but sometimes related to neoplasia, infections, demyelinating condit
ions, connective tissue disorders, other disorders, or, occasionally, drugs
. This paper reports on a patient with sudden-onset trigeminal sensory neur
opathy of the lip that proved to be drug-induced, secondary to the anti-mal
arial drug mefloquine. This appears to be the first report of sensory impai
rment in the orofacial region from exposure to mefloquine.