Wickham's striae

• these are thin, pearly white structures arranged in a reticular pattern that is observed over lichen planus lesions and histologically correspond to epidermal hypergranulosis. They are usually most visible on the oral mucosa but can also cover almost every active lichen planus papule.
• Wickham's striae are easier to spot if you apply a thin layer of oil to the surface of the top of the lichen planus lesions

Reference:

1. Fagotto L et al. Wickham striae on skin appendages: a helpful dermoscopic feature. Dermatol Reports. 2023 Jun 6;15(3):9698