Oral lichen planus: A disease or a spectrum of tissue reactions? Types, causes, diagnostic algorithms, prognosis, management strategies.

Oral lichen planus: A disease or a spectrum of tissue reactions? Types, causes, diagnostic algorithms, prognosis, management strategies.

The etiology of oral lichen planus is currently unknown. There is much debate about if it is a disease or a spectrum of tissue reactions. Furthermore, there is debate about certain terminology used. Two terms often used to refer to this tissue disorder are oral lichen planus and oral lichenoid lesions. A review article published June 2019 in the journal Periodontology 2000, takes a deep look at this elusive disorder of the oral mucosa.1

It may surprise you that there are 13 different classifications and characteristics of oral lichenoid lesions. Oral lichen planus is the preliminary disorder of the classifications. It is believed that oral lichen planus is relatively common, affecting approximately 1-2% of the population. Oral lichen planus is a chronic disorder that causes significant discomfort and it has been postulated that it is possible the lesions can become malignant. When oral lichen planus presents as erosive or ulcerative lesions it can be confused with diseases such as pemphigus vulgaris, mucous membrane pemphigoid, and persistent erythema multiforme. It is believed that oral lichen planus is a T-cell mediated immunological response to an unknown antigenic change in the oral mucosa. 

Oral lichenoid contact lesion is a term used to describe oral lesions that are found to resemble oral lichen planus both clinically and histopathological. However, they are thought to be caused by a localized reaction to dental materials, the primary suspect being amalgam. Though studies are conflicting on the relevance of amalgams being the source of these lesions, proximity to amalgams is often reported. It is important to mention currently there is not enough evidence to support the removal of amalgam restorations in patients that present with these lesions. 

Oral lichenoid drug reactions are, as the name implies, caused by or associated with certain medications. The list of drugs that can cause these lesions is quite lengthy and include angiotensin-converting enzyme inhibitors, NSAIDs, oral hypoglycemic drugs, penicillamine, beta-blockers, methyldopa, quinidine, and quinine, diuretics, antifungals, anticonvulsants, immunomodulatory drugs, sulfasalazine, and lithium.

Graft vs. host disease is a condition that occurs when donor bone marrow or stem cells attack the recipient. Patients that suffer from chronic graft vs. host disease often experience orofacial manifestations, it is estimated that 80% will experience some type of orofacial manifestation. Some of these manifestations include oral lichenoid lesions including reticulations, ulceration, and mucosal atrophy, salivary gland dysfunction, and orofacial fibrosis.

Other diseases or disorders listed in the classification criteria of lichen planus include lichen planus-like variant of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome, discoid lupus erythematosus, systemic lupus erythematosus, chronic ulcerative stomatitis, and lichen planus pemphigoids. 

Management of oral lichen planus/oral lichenoid lesions can be challenging. Oral lichen planus, oral lichenoid contact lesions, discoid lupus erythematosus, and chronic ulcerative stomatitis often respond well to topical therapy, while paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome, systemic lupus erythematosus, and lichen planus pemphigoids require additional systemic medications. Topical corticosteroids are the first line of treatment for oral lichen planus/oral lichenoid lesions. Other topical treatments incorporated are immunosuppressants or immunomodulatory agents such as calcineurin inhibitors or retinoids.

Patients that fail to respond to topical treatments may need systemic therapy. Systemic corticosteroids such as prednisolone administered at a starting dose of 40-80 mg daily for 1-4 weeks usually provide a substantial improvement. However, due to the chronic nature of oral lichen planus/oral lichenoid lesions, oral corticosteroids are not the most sensible option. Other immunosuppressants such as azathioprine and mycophenolate mofetil are preferred for long term use. More recently certain biologic agents have been considered for treatment.

A few novel treatments have been suggested. These include topical aloe vera and oral curcuminoids. It is important to mention the amount of active ingredient in aloe vera can vary, and there are notable side effects associated with the use of oral curcuminoids that affect up to 40% of patients that use it including liver dysfunction.

Most importantly, many of the disorders associated with oral lichen planus/oral lichenoid lesions have been shown to increase the risk of oral cancer development. This knowledge should keep clinicians vigilant in oral cancer screenings to assess any suspicious changes.

Have you had trouble in managing patients with oral lichen planus? Haver your patients with oral lichen planus given any indication of what works best for them? Have you had to refer a patient for a biopsy due to visual changes in oral lichenoid lesions?

 

1. Carrozzo M, Porter S, Mercadante V, Fedele S. Oral lichen planus: A disease or a spectrum of tissue reactions? Types, causes, diagnostic algorithms, prognosis, management strategies. Periodontol 2000. 2019;80(1):105–125. doi:10.1111/prd.12260

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