Erosive lichen planus (ELP) most typically affects the oral mucosa or genitals. However, it may rarely involve the eyelids, esophagus, larynx, anus, bladder, or external auditory canal.[15][16][17] Patients develop painful, erythematous erosions and ulcerations, which may be present for several months or longer.

Vulvar and vaginal erosive lichen planus typically presents with complaints of pain, dysuria, a burning sensation, and dyspareunia, often with post-coital bleeding.[18] Patients may also notice blood-tinged vaginal discharge. Lesions are characterized by glazed appearing, erythematous erosions, and patches with well-demarcated borders. White, serpiginous striae, known as Wickham striae, are often seen around the border.[19] Lesions tend to be symmetrical and bilateral. Lesions tend to heal slowly, and recurrent exacerbations are very common. Architectural change, including scarring, loss of the labia minora, and narrowing or obliteration of the vagina may occur, especially if erosive LP is left untreated.[19]

In oral erosive LP, lesions may occur on the buccal mucosa, labial mucosa, tongue, or vermillion border. Often, the lesions are bilateral and symmetrical.[20] The often severe pain associated with these ulcers may lead to anorexia, weight loss, nutritional deficiencies, and depression.[21] Mucosal bleeding may occur with minimal trauma, such as with tooth brushing. The development of new erosions at sites of minimal trauma, known as the Koebner phenomenon, is also common.[21] Compared to aphthous ulcers, lesions of erosive LP are typically larger, have irregular shapes, and usually do not resolve for at least several weeks. Desquamative gingivitis, which is the development of widespread gingival erosions, may also result from erosive LP.[22] After the eventual resolution of erosive lesions, scarring and post-inflammatory hyperpigmentation are very common.[20]

Vulvovaginal-gingival (VVG) syndrome is a specific variant of erosive lichen planus, which involves the vulva, vagina, vestibule, and oral mucosa, as well as potential additional sites, such as the skin and esophagus.[23][24] The involvement of all three areas is common; however, lesions typically do not occur concurrently. VVG is often particularly refractory to treatment.[25]

Diagnosis of erosive lichen planus is most often made based on a presentation with a typical history and clinical appearance. The biopsy of the lesion is usually performed when the diagnosis is in question or to rule out malignancy. As mentioned above, ulceration of the lesion may result in the absence of the characteristic lichenoid features on histology.[8]

Regardless of the location of the patient’s symptoms, full evaluation of the cutaneous and mucosal surfaces should be performed when lichen planus is suspected. Patients with lichen planus frequently present with manifestations in more than one location. A thorough review of other systems should also be obtained to identify any symptoms suggestive of mucosal involvement, such as esophagus, conjunctiva, urethra, anus, or larynx. Untreated erosive lichen planus frequently progresses to scarring and functional impairment, especially when undiagnosed and untreated.[26] Screening for an unknown diagnosis of hepatitis C should also be considered.

Management of erosive lichen planus is often challenging for both the patient and the provider. Treatment response is often poor, and relapses are common. Topical corticosteroids have been shown in a randomized control trial to be effective for oral lichen planus and are the mainstay of treatment for both genital and oral erosive lichen planus.[27] 

Topical steroids are generally applied for courses of 4 to 6 weeks in the acute setting, with maintenance therapy often being necessary for the long term. For genital erosions, ultra-potent steroid ointment or cream should be applied to the lesion daily. A stepwise lowering of application frequency should be performed after remission has been achieved to minimize the risk of side effects while still preventing relapse. For oral disease, ultra or high potency topical steroids are recommended. The application should occur 3 to 4 times per day in the acute setting and should be performed after the site has been dried.

The gingival disease may be treated by either rinsing with oral elixirs or with the aid of a gingival tray.[28] For second-line therapy, topical calcineurin inhibitors such as tacrolimus and pimecrolimus are effective in both oral and vulvar LP.[29][30] For patients with severe erosive LP, initiating a four to six-week course of oral prednisone, tapered down from 40-60mg daily, may prove beneficial.[31][32] For refractory disease, many systemic treatments such as methotrexate, mycophenolate, minocycline, cyclosporine, trimethoprim-sulfamethoxazole, hydroxychloroquine, and acitretin have been utilized, but overall data regarding their efficacy is lacking.[33][34]

Pain is often a significant symptom in erosive LP. Topical anesthetics such as viscous lidocaine frequently prove useful, especially in patients who have decreased oral intake due to painful oral LP. For vulvar and vaginal erosive LP, dilators and surgery can often help correct anatomic distortions due to adhesions and scarring.

The differential diagnosis for erosive lichen planus may vary based on the affected location.

• Crohn disease may present with erosions of the oral cavity, vulva or perineum, or anus, and may present years before any bowel findings.[35]
• Autoimmune bullous diseases may present clinically identical to erosive LP and can be differentiated by immunofluorescence studies.[36]
• Behcet syndrome, erythema multiforme, and Stevens-Johnson syndrome all may present in ways clinically similar to erosive LP.
• When affecting the female genitalia, erosive LP may be confused with lichen sclerosus. However, unlike erosive LP, lichen sclerosus rarely affects the vagina or oral mucosa.[37]
• Other disorders of the genitalia that should be considered include plasma cell vulvitis, vulvar intraepithelial neoplasm, and atrophic vaginitis.
• When occurring in the oral cavity, the differential for erosive LP should consist of oropharyngeal candidiasis, leukoplakia, squamous cell carcinoma, leukoedema, and allergic contact mucositis.

The lesions of erosive lichen planus are often persistent and tend to respond poorly to therapy.[38] Bouts of the disease usually last for years, and relapses are frequent even when maintenance therapy is appropriately utilized.[38]

Patients with erosive lichen planus are at significant risk of developing secondary infections. This risk is especially high for the development of candidiasis, staphylococcus aureus cellulitis, and herpes simplex.[39] Oral lichen planus has been shown in a systemic review to carry an approximate rate of transformation to squamous cell carcinoma of 1%, which is thought to be the result of chronic mucosal inflammation.[40]

A similar risk of development of squamous cell carcinoma has also been found in penile and vulvar lichen planus, although the rates of transformation have been less clearly identified.[41][42] Scarring is also a frequent complication of erosive lichen planus, which may lead to interference with intercourse, urination, and eating.

Patients should be educated on the clinical course and potential complications of erosive lichen planus. Smoking cessation and HPV vaccination should be advised to minimize the risk of transformation to squamous cell carcinoma.

Erosive lichen planus is a chronic, often debilitating disease that can affect many organ systems. Specialists such as dermatologists, dentists, and gynecologists may be needed to work together to coordinate the delivery of optimal patient care. A multi-disciplinary approach should be taken in accordance with the patient’s symptoms and goals of treatment.