What is erosive lichen planus?
Erosive lichen planus is a chronic and painful condition affecting mucosal surfaces, mainly the mouth (oral lichen planus) and the genitals (vulval or penile lichen planus).
A severe variant or erosive lichen planus in women is known as the vulvovaginal gingival syndrome. Ulceration occurs in the mouth and gums as well as on the vulva and in the vagina. Peno-gingival syndrome is the equivalent condition in men.
Erosive lichen planus is sometimes associated with classical cutaneous lichen planus or other forms of mucosal lichen planus.
Who gets erosive lichen planus?
Erosive lichen planus most often affects people in their 40s to 70s. It is at least twice as common in women than in men.
What causes erosive lichen planus?
Erosive lichen planus is a destructive autoimmune disease of unknown cause involving T lymphocytes.
- Occasionally, it is drug-induced and will resolve on withdrawal of the responsible drug.
- Partial response to antifungal agents and antibiotics indicates an abnormal response to local microflora may be involved, especially Candida albicans.
- Cytokine expression profiling has found increased levels of the interleukins, IL-17 and IL-23.
What are the clinical features of erosive lichen planus?
Erosive lichen planus causes painful and persistent ulcers. These heal with scarring. It mainly affects adults, particularly women, and is rare in children.
Oral erosive lichen planus
In the mouth, erosions and ulcers may be the only signs (ulcerative stomatitis). They may occur inside the cheeks, on the sides of the tongue, on the gums, or inside the lips. Unlike short-lasting aphthous ulcers, erosive lichen planus lesions are larger and more irregular, and they may persist for weeks or longer. It can be very painful to eat, resulting in weight loss, nutritional deficiencies and depression.
Other forms of oral lichen planus may also occur, including white lacy streaks and inflammation and peeling of the gums (desquamative gingivitis).
Oral erosive lichen planus
Genital erosive lichen planus
In women, erosive lichen planus affects the labia minora (inner lips) and introitus (entrance to the vagina). The affected mucosa is bright red and raw. Erosive lichen planus can be very painful, stinging when passing urine and preventing sexual intercourse. It is one cause of vulvodynia (burning discomfort of the vulva). Erosive lichen planus may also result in very severe itch.
The clitoral hood may disappear, and the labia minora can shrink and stick to each other or to the labia majora (the outer lips). It can also scar, closing over the vagina.
Sometimes erosive lichen planus affects deep within the vagina where it causes inflammation and superficial ulceration (desquamative vaginitis). The surface cells in the vagina peel off and cause a mucky discharge. The eroded vagina may bleed easily on contact.
Erosive lichen planus in men affects the end of the penis (the glans), which becomes red, raw and tender.
Images of erosive lichen planus affecting the vulva
Other mucosal sites
Erosive lichen planus rarely affects the eyelids, external ear canal, oesophagus, larynx, bladder and anus.
What is the cause of erosive lichen planus?
The cause or causes of erosive lichen planus are unknown. It is considered an autoimmune disease, where immune cells called T-lymphocytes attack the epidermal cells of affected areas.
Erosive lichen planus is not due to infection or allergy.
What are the complications of erosive lichen planus?
Patients with erosive lichen planus may develop infections particularly Candida albicans, herpes simplex, Staphylococcus aureus. Herpes infections are particularly painful and may cause vulval ulceration.
Squamous cell carcinoma
In about 1–3% of cases, longstanding erosive lichen planus can result in cancer (squamous cell carcinoma, SCC) of the mouth (oral cancer), vulva (vulval cancer) and penis (penile cancer). This should be suspected if there is an enlarging lump or an ulcer with thickened edges.
Some patients with erosive lichen planus have a particularly high risk of SCC:
- Patients that are immune suppressed due to disease or drugs
- Patients infected with oncogenic types of human papillomavirus (HPV, see genital warts).
Erosive lichen planus is a destructive disorder. Even when the inflammatory component has resolved, scarring may interfere with eating or sexual function.
How is erosive lichen planus diagnosed?
The diagnosis of erosive lichen planus is often made by the typical history and clinical appearance. A biopsy may be recommended to confirm the diagnosis and to look for cancer. Histopathological signs of a ‘lichenoid tissue reaction’ affecting the epidermis (the skin cell layer) are supportive.
However, the ulcerating nature of the disorder means that the epidermis may be missing so that lichenoid features may not be observed. The pathologist may describe a brisk inflammatory infiltrate in the mucosa, but this is non-specific.
Direct immunofluorescent staining of tissue may also be helpful.
What is the treatment of erosive lichen planus?
The management of erosive lichen planus may be very challenging. As it is a chronic complaint, topical and systemic treatment may be required intermittently or continuously, long-term.
For oral disease, it is important to practice good oral hygiene and to have regular dental check-ups. Avoid foods that make the mouth sore.
The genitals should be gently washed using water alone or with a non-soap cleanser such as aqueous cream. A non-irritating emollient such as petrolatum may be applied as desired.
Ultrapotent topical steroids
Topical steroids generally applied daily for 4 to 6-week courses. They are the mainstay of therapy in most patients but maintenance treatment 1–3 times per week or more often may be necessary long-term.
- In the mouth, topical steroids may be supplied as a paste, nasal spray (intended for rhinitis) or asthma-preventive puffer. These should be applied to the eroded areas two or three times daily.
- For genital erosions, ultrapotent steroid ointment (eg clobetasol propionate) should be applied to the affected area as a thin smear once daily. Cream may be preferred, but is more likely to sting on application.
- Hydrocortisone foam can be used inside the vagina or anus.
Calcineurin inhibitors such as pimecrolimus cream or tacrolimus ointment have proven very effective for some patients with erosive lichen planus. These are applied once or twice daily for several weeks. Treatment may be repeated as required.
Mouthwashes containing ciclosporin or tacrolimus have been found to help oral disease.
Systemic steroids such as prednisone may be prescribed for a few weeks or longer, usually at a dose of 0.5–1 mg/kg/day. Once the erosions have healed, the dose is tailed off. Longterm use of systemic steroids may have serious side effects. In many patients, calcium and vitamin D should also be prescribed to reduce the chance of corticosteroid-induced bone thinning.
Methotrexate is taken in a dose of 10–20mg once weekly. Folic acid is often added to reduce the chance of potential adverse effects. This may be very effective for erosive lichen planus, with improvement or healing occurring within one to three months. It may be continued long-term if required. Blood count, liver function and procollagen levels should be monitored. Alcohol intake should be minimised. It must not be taken during pregnancy.
Other oral treatments
Other drugs that sometimes help include:
- Mycophenolate mofetil
- Oral antibiotics, such as a tetracycline
- Oral antifungal agents
Surgical release of vulval and vaginal adhesions and scarring from lichen planus may occasionally be performed to reduce urination difficulties and allow intercourse. Procedures may include:
- Dilation of the vagina
- Simple perineotomy (the division of adhesions)
- Fenton procedure (an incision that is repaired transversely)
- Perineoplasty (excision of involved tissue and vaginal mucosal advancement)
Other treatments that have been tried include photodynamic therapy and focused ultrasound therapy.