Lichen planus is best described as which of the following?

• A. A contagious bacterial infection
• B. A fungal infection
• C. A form of tooth decay
• D. A non-infectious, itchy rash

Answer: (D)

Lichen planus is an autoimmune inflammatory condition that affects skin and mucous membranes, not caused by bacteria or fungi and not contagious. In the mouth you may see white, lacy patches known as Wickham's striae, sometimes with red, irritated areas that can itch or be uncomfortable. Because it is non-infectious, the best description is a non-infectious, itchy rash. It’s not a contagious bacterial infection, not a fungal infection, and not tooth decay. In dental practice, recognizing this helps distinguish it from infections or caries, guiding appropriate monitoring, oral care advice, and referral if the diagnosis is uncertain or lesions change.