A 55-year-old man presented with painful, burning sores in his mouth for several weeks,
aggravated by eating spicy foods and caffeine-containing drinks. Examination showed multiple irregularly shaped erosions with yellow bases and a few white circular areas on the inside of both cheeks (the buccal mucosae). An oral biopsy confirmed the diagnosis of erosive lichen planus. He was treated with a medium-strength topical steroid gel called fluocinonide twice daily for two weeks.
At the follow-up visit, he complained that his symptoms were worse. The mucous membranes now demonstrated white raised patches that could be wiped away by the examiner to reveal bases with bleeding points. Microscopic examination of the surface cells also showed many pseudohyphae indicative of a yeast infection or thrush. A culture of this material later grew Candida albicans yeast. The steroid gel was stopped, and he was asked to take clotrimazole lozenges to dissolve in his mouth five times daily for two weeks.
At the next follow-up visit, his mouth felt completely normal, and the examination showed that his mucous membranes were virtually clear. No further treatment was given.
Oral lichen planus is frequently colonized by yeast organisms such as Candida species. When steroid medicines such as topical gels , rinses, and pills are used to reduce the inflammation caused by the lichen planus disease, the local immunity is suppressed. This allows further growth of yeast colonies, invasion of the superficial layer of the mucous membrane, and development of a true yeast infection called “thrush” in the mouth.
What we have learned from this experience is to either treat the presumed yeast infection first, or to combine the anti-yeast and anti-inflammatory steroid treatment from the outset. We do this routinely now by alternating the oral rinses dexamethasone which is the steroid with nystatin which is the anti-yeast agent with fairly successful results. There are other choices of steroids and anti-yeast agents available as well as non-steroidal medications for the more resistant cases of oral erosive lichen planus.