Erosive lichen planus (ELP) is a variant of lichen planus which involves chronic and painful ulceration of the skin and mucosal surfaces. ELP is thought to be the result of autoimmune damage of the basal cell layer, which is mediated by activated CD8 T lymphocytes.[1] Occasionally, ELP may present in conjunction with other clinical forms of lichen planus or may be induced by drug exposure. Clinical findings include painful, persistent ulcers, primarily of the mouth and genitals.[2] Complications of ELP include secondary infection, development of squamous cell carcinoma, and scarring
Causes of Erosive lichen planus (ELP)
Lichen planus (LP) is thought to be a T-cell mediated auto-immune inflammatory disorder, which destroys basal epithelial cells.[1] CD8 T cells are considered primary offending cells based on biopsy specimens. It is believed that the presentation of exogenous antigens, such as viruses, metals, or drugs, may lead to CD8 activation and destruction of keratinocytes.[3] LP has also been associated with other auto-immune diseases, including vitiligo, auto-immune thyroid disease, and alopecia areata.[4]
Hepatitis C is well known to be associated with LP, although the link between HCV and erosive LP has not been established. Odds ratios of up to 5.4 for HCV positivity were found among patients with LP. However, this association was not significant statistically among all geographic groups in further analysis.[5] Like other forms of LP, erosive LP may be drug-induced and often resolves with the removal of the offending agent.[6]
Diagnosis of Erosive lichen planus (ELP)
Histopathology
The diagnosis of erosive lichen planus (ELP) is typically made by history and clinical exam. However, biopsy helps to confirm the diagnosis and rule out the potential for malignancy. On histopathology, typical findings include hyperkeratosis without parakeratosis, liquefaction of the basal layer, saw-toothed rete ridges, Civatte bodies (eosinophilic masses representing apoptotic keratinocytes), and a band-like lymphohistiocytic infiltrate near the dermal-epidermal border.[7] Unfortunately, the presence of ulceration, leading to the absence of the epidermis, often prevents many of these features from being observed. In such cases, biopsy specimens often appear very non-specific.[8] Direct immune-fluorescence is also helpful in ruling out immune-bullous disorders.
History and Physical
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]
Evaluation
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.
Treatment of Erosive lichen planus (ELP)
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.
