Seventeen patients with oral lichen planus, two of them also with lichen planus patches on the glans penis, were treated with vitamin A acid. The systemic effect resulted in regression of discrete and leukoplakia-like papules. Linear pattern of the oral mucosa and lichen-planus patches of the glans penis showed distinct involution only by topical administration of the agent. Recurrences were observed in two patients. The side effects of such treatment are mentioned.
Günther SH. Vitamin A Acid in Treatment of Oral Lichen Planus. Arch Dermatol. 1973;107(2):277. doi:10.1001/archderm.1973.01620170085024