Lichen planus (lichen ruber planus) is an immune-mediated disease of the skin and mucous membranes with unknown aetiology.
A number of patients with oral lichen planus also have the cutaneous form of the disease. Cutaneous manifestations are episodic, oral manifestations are long-term.
Treatment essentially consists of elimination of factors that possibly irritate the mouth. Symptoms can be alleviated with short-term courses of topical glucocorticoids.
Follow-up is important, because oral lichen planus can turn malignant.
Epidemiology
Found in about 1-2% of the population.
Two thirds of the patients are female. The incidence is highest at middle-age.
Symptoms and diagnosis
Oral lichen planus is divided into the following types, according to its clinical manifestation: papular, reticular, plaque-like, atrophic, erosive and bullous. The reticular type, with pale Wickham's striae on the mucous membranes (pictures 12), is the most common form of the disease. Changes of different types may co-exist.
The lichen planus lesions always show symmetrical distribution, most typically over the buccal mucosa, the tongue (picture 3) and/or the gums.
A number of patients with oral lichen planus also have skin manifestations of the disease Lichen Planus. Lesions may also be found e.g. in the genital region, in the oesophagus and on the scalp.
The disease is often accompanied by secondary oral fungal infection which worsens the symptoms.
Diagnosis is based on the clinical picture which should, if needed, be confirmed with biopsy.
Treatment
Cornerstones of treatment consists of the elimination of any possible aggravating factors (dental calculus, sharp edges of dental fillings, rubbing prosthesis, irritating foods, irritating mouth care products), good oral hygiene and treatment of possible Fungal Infections (before treatment with glucocorticoids; confirm diagnosis with a fungal culture).
In addition, topical glucocorticoids can be used for symptom relief as short-term courses (e.g. for 2-3 weeks), e.g.
A good method to apply glucocorticoid ointment to lesions situated predominantly on the gums is the use of medicinal spoons.
An ex-tempore anaesthetic gel (containing betamethasone, an antifungal, e.g. nystatin, chlorhexidine and lidocaine) can be used as first-aid help for short-term use in acute, painful conditions.
In severe cases lesions may also be injected directly with glucocorticoids.
Tacrolimus or pimecrolimus ointment can be used short-term if glucocorticoids do not provide satisfactory response.
In highly refractory forms, systemic treatment with glucocorticoids or other immunosuppressive agents may be considered.
N.B. Approximately 1% of oral lichen planus lesions become malignant. Follow-up is warranted at least once a year together with checking the mouth and teeth. Photographing any changes is recommended. A repeat biopsy is taken as necessary.
Lichenoid reactions
Lichenoid reactions do not completely fulfil the clinical and histopathological criteria for lichen planus.
Often a single, localized lesion (compare with lichen planus)
An aetiological factor cannot always be identified.
Treatment
Removal of the cause if identifiable
Symptomatic treatment as in lichen ruber planus
Also lichenoid reactions are probably associated with a 2.5% risk of oral squamous cell carcinoma.
References
Kurago ZB. Etiology and pathogenesis of oral lichen planus: an overview. Oral Surg Oral Med Oral Pathol Oral Radiol 2016;122(1):72-80. [PubMed]
Lodi G, Carrozzo M, Furness S et al. Interventions for treating oral lichen planus: a systematic review. Br J Dermatol 2012;166(5):938-47. [PubMed]
Cheng YS, Gould A, Kurago Z ym. Diagnosis of oral lichen planus: a position paper of the American Academy of Oral and Maxillofacial Pathology. Oral Surg Oral Med Oral Pathol Oral Radiol 2016;122(3):332-54. [PubMed]
García-Pola MJ, González-Álvarez L, Garcia-Martin JM. Treatment of oral lichen planus. Systematic review and therapeutic guide. Med Clin (Barc) 2017;149(8):351-362. [PubMed]
Olson MA, Rogers RS 3rd, Bruce AJ. Oral lichen planus. Clin Dermatol 2016;34(4):495-504. [PubMed]