Cheilitis Oscura

The patient is a 59 yo woman with a four month history of a pruritic dermatitis of the upper lip. It is spreading to the lower lip. She uses Crest toothpaste, a white ceramic nasal irrigator, dental floss, a WaterPic and a Sonic Dental Care apparatus on a daily basis. She has used Desonide ointment for three to four weeks with minimal help.




















Presumably, this is an allergic contact dermatitis.
She was patch tested today. If this is negative, I will probably do a biopsy and if that is not helpful refer her to a center that does more in-depth patch testing. I suspect that part of her regimen is the culprit. In children, lip licking should be considered (lick eczema) but the history here does not support that diagnosis.

Question?: Have you encountered similar cases? What are your thoughts?