A 49-year-old woman was referred to an oral pathology practice for evaluation of swelling noted in the lower lip of 2 weeks duration. She stated that the swelling was preceded by a feeling of 2 areas of nodularity in the lower left labial mucosa 24 hours before its onset. The swelling was more marked on waking in the morning. She took multiple systemic medications, including an antihistamine and an antiviral drug, with no improvement; at the time of the evaluation, she was taking naproxen daily, which she believed had reduced the extent of the swelling.