A young male presented with scaly truncal lesions. O/E genital lesions along with oral 'lace-like' lesions are seen. The most likely diagnosis is:

In oral lichen planus, the characteristic lesions are white striae or papules forming a reticular lace like pattern on the buccal mucosa or lateral margins of the tongue, often with a bilaterally symmetrical distribution. Ref: Principles and Practice of Geriatric Medicine edited by M.S. John Pathy, Alan J. Sinclair, John E. Morley, 2006, Page 265