Comment
Clinical Presentation—Lichen planus—CLP and OLP—most frequently presents between the ages of 40 and 60 years, with a slight female predilection.1,2 The lesions typically present with the 5 P’s—purple, pruritic, polygonal papules and plaques—with some lesions revealing white lacy lines overlying them called Wickham striae.6 The lesions may be red at first before turning purple. They often present on the flexural surfaces of the wrists and ankles as well as the shins and back but rarely affect the face, perhaps because of increased chronic sun exposure.2,6 Less common locations include the scalp, nails, and mucosal areas (eg, oral, vulvar, conjunctival, laryngeal, esophageal, anal).1
If CLP is diagnosed, the patient likely will also have oral lesions, which occur in 50% of patients.2 Once any form of lichen planus is found, it is important to examine all of the most frequently involved locations—mucocutaneous and cutaneous as well as the nails and scalp. Special care should be taken when examining OLP and genital lichen planus, as long-standing lesions have a 2% to 5% chance of transforming into squamous cell carcinoma.2
Although cases of traditional OLP and CLP are ubiquitous in the literature, ELP rarely is documented because of frequent misdiagnoses. Esophageal lichen planus has a closer histopathologic resemblance to OLP compared to CLP, and its highly variable presentation often results in an inconclusive diagnosis.3 A review of 27 patients with lichen planus highlighted the difficult nature of diagnosing ELP; ELP manifested up to 20 years after initial lichen planus diagnosis, and patients underwent an average of 2.5 dilations prior to the successful diagnosis of ELP. Interestingly, 2 patients in the study presented with ELP in isolation, which emphasizes the importance of secondary examination for lichen planus in the presence of esophageal strictures.7 The eTable provides common patient demographics and symptoms to more effectively identify ELP.Differential Diagnosis—Because lichen planus can present anywhere on the body, it may be difficult to differentiate it from other skin conditions. Clinical appearance alone often is insufficient for diagnosing lichen planus, and a punch biopsy often is needed.2,20 Cutaneous lichen planus may resemble eczema, lichen simplex chronicus, pityriasis rosea, prurigo nodularis, and psoriasis, while OLP may resemble bite trauma, leukoplakia, pemphigus, and thrush.20 Dermoscopy of the tissue makes Wickham striae easier to visualize and assists in the diagnosis of lichen planus. Furthermore, thickening of the stratum granulosum, a prevalence of lymphocytes in the dermoepidermal junction, and vacuolar alteration of the stratum basale help to distinguish between lichen planus and other inflammatory dermatoses.20 A diagnosis of lichen planus merits a full-body skin examination—hair, nails, eyes, oral mucosa, and genitalia—to rule out additional involvement.
Esophageal lichen planus most frequently presents as dysphagia, odynophagia, and weight loss, but other symptoms including heartburn, hoarseness, choking, and epigastric pain may suggest esophageal involvement.4 Typically, ELP presents in the proximal and/or central esophagus, assisting in the differentiation between ELP and other esophageal conditions.3 Special consideration should be taken when both ELP and gastroesophageal reflux disease are considered in a differential diagnosis, and it is recommended to pair an upper endoscopy with pH monitoring to avoid misdiagnosis.8 Screening endoscopies also are helpful, as they assist in identifying the characteristic white webs, skin peeling, skin surface erosion, and strictures of ELP.4 Taken together, dermatologists should encourage patients with cutaneous or mucocutaneous lichen planus to undergo an esophagogastroduodenoscopy, especially in the presence of any of ELP’s common symptoms (eTable).
Etiology—Although the exact etiology of lichen planus is not well established, there are several known correlative factors, including hepatitis C; increased stress; dental materials; oral medications, most frequently antihypertensives and nonsteroidal anti-inflammatory drugs; systemic diseases; and tobacco usage.6,21
Dental materials used in oral treatments such as silver amalgam, gold, cobalt, palladium, chromium, epoxy resins, and dentures can trigger or exacerbate OLP, and patch testing of a patient’s dental materials can help determine if the reaction was caused by the materials.6,22 The removal of material contributing to lesions often will cause OLP to resolve.22
It also has been suggested that the presence of thyroid disorders, autoimmune disease, various cancers, hypertension, type 2 diabetes mellitus, hyperlipidemia, oral sedative usage, and/or vitamin D deficiency may be associated with OLP.21,23 Although OLP patients who were initially deficient in vitamin D demonstrated marked improvement with supplementation, it is unlikely that vitamin D supplements impacted our patient’s presentation of OLP, as she had been consistently taking them for more than 5 years with no change in OLP presentation.24