Patients should be questioned about their medication history, any history of pruritus or genital pain and history of dysphagia or odynophagia. Examination of entire cutaneous surface including the scalp, oral cavity and external genitalia need to be included. Wickhams striae often can be seen during microscopic examination of cutaneous lesions of lichen planus.To confirm the diagnosis of cutaneous lichen planus, a skin biopsy can be done. A punch biopsy of sufficient depth to the mid dermis is usually significant. Immunofluorescence studies are not always needed. Direct immunofluorescence (DIF) can be useful in patients with bullous lesions to differentiate the condition from an autoimmune vesiculobullous disease. Mouth
A diagnosis of oral lichen planus (LP) is confirmed through review of the patient history, physical examination, and histologic findings.The clinical evaluation should include a patient history that assesses the following:

History of LP involving other body sites or other skin disorders that may present with similar findings (e.g., autoimmune blistering diseases)
Presence of associated symptoms (e.g., pain, burning)
Medication the patients are taking within the few weeks to months after drug initiation e.g. antihypertensives, antidepressants, diuretics, antidiabetics, NSAIDs, etc. to evaluate for the possibility of an oral lichenoid drug eruption
History of dental restorations, use of dental appliances, or oral exposure to substances that may cause oral lichenoid contact eruptions (e.g. dental composites, cobalt chromium based dentures etc. )A full examination that includes the evaluation of the mucosal and cutaneous surfaces, including the vulva, vagina, penis, scalp, and nails should be performed.
About 50% of females with oral lichen planus were reported to have undiagnosed vulvar lichen planus.Some studies suggest that cutaneous lichen planus is more commonly found in men whilst oral lichen planus lesions are more commonly found in women. History
Lichen planus was first reported in 1869 by Erasmus Wilson.The origin of the word is believed to be from the Greek word Leichen, which means tree moss, and also from Latin word planus, which means flat and even surface. Dr Wilson explained the condition as an inflammatory disorder with unknown etiology. Initially, the characteristic surface markings or striae was described by Weyl in 1885. In 1895, Wickham further explained the characteristic of the lesion, now known as Wickham striae. Further on, Darier explained the presence of such characteristic markings by correlating with an increase thickness of the granular cell layer. The coexistence of oral, cervical and stomach lichen planus lesions were described by Guogerot and Burnier in 1937. A similar variant of mucosal lichen planus as the vulvovaginal-gingival syndrome with erosive lesions involving oral and vulvovaginal mucosa were introduced by Pelisse and colleagues in year 1982. Research
Apremilast is undergoing investigation as a potential treatment. Notes
References
External links

Lichen planus at Curlie