Restated, this is a cutaneous condition usually characterized by a solitary dusky-red to violaceous papular skin lesion. Lichenoid dermatitis represents a wide range of cutaneous disorders characterized by lichen planus-like skin lesions. Mucous membranes
Lichen planus affecting mucosal surfaces may have one lesion or be multifocal. Examples of lichen planus affecting mucosal surfaces include:
Esophageal lichen planus, affecting the esophageal mucosa. This can present with difficulty or pain when swallowing due to oesophageal inflammation, or as the development of an esophageal stricture. It has also been hypothesized that it is a precursor to squamous cell carcinoma of the esophagus. Genital lichen planus, which may cause lesions on the glans penis or skin of the scrotum in males, and the vulva or vagina in females. Symptoms may include lower urinary tract symptoms associated with stenosis of the urethra, painful sexual intercourse, and itching. In females, Vulvovaginal-gingival syndrome, is severe and distinct variant affecting the vulva, vagina, and gums, with complications including scarring, vaginal stricture formation, or vulva destruction. The corresponding syndrome in males, affecting the glans penis and gums, is the peno-gingival syndrome. It is associated with HLA-DQB1. Mouth
Oral lichen planus (also termed oral mucosal lichen planus), is a form of mucosal lichen planus, where lichen planus involves the oral mucosa, the lining of the mouth. This may occur in combination with other variants of lichen planus. Six clinical forms of oral lichen planus (OLP) are recognized:
These types often coexist in the same individual.
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.