Lichen planus
Encyclopedia
Lichen planus is a chronic mucocutaneous disease that affects the skin
, tongue, and oral mucosa
. The disease presents itself in the form of papule
s, lesion
s, or rash
es. Lichen planus does not involve lichen
s, the fungus/algae symbionts that often grow on tree trunks; the name refers to the dry and undulating, "lichen-like" appearance of affected skin. It is sometimes associated with certain medications and diseases, but is basically of unknown cause.
Oral lichen planus (OLP) may present in one of three forms.
The microscopic appearance of lichen planus is pathognomonic for the condition
Lichen planus may also affect the genital mucosa – vulvovaginal-gingival lichen planus. It can resemble other skin conditions such as atopic dermatitis
and psoriasis
.
Rarely, lichen planus shows esophageal involvement, where it can present with erosive esophagitis and stricturing. It has also been hypothesized that it is a precursor to squamous cell carcinoma of the esophagus.
Clinical experience suggests that Lichen planus of the skin alone is easier to treat as compared to one which is associated with oral and genital lesions.
Nail & hair loss is irreversible.
and does not involve any known pathogen
. Some lichen planus-type rashes (known as lichenoid reactions) occur as allergic reactions to medications for high blood pressure, heart disease
and arthritis
, in such cases termed drug-induced lichenoid reaction
s. These lichenoid reactions are referred to as lichenoid mucositis (of the mucosa) or dermatitis (of the skin). Lichen planus has been reported as a complication of chronic hepatitis C
virus infection and can be a sign of chronic graft-versus-host disease
of the skin (Lichenoid reaction of graft-versus-host disease
). . It has been suggested that true lichen planus may respond to stress
, where lesions may present on the mucosa or skin during times of stress in those with the disease. Lichen planus affects women more than men (at a ratio of 3:2), and occurs most often in middle-aged adults. The involvement of the mucous membranes is seen frequently and usually is asymptomatic, but occasionally, LP can be complicated by extensive painful erosions. Lichen planus in children is rare. In unpublished clinical observation, lichen planus appears to be associated with hypothyroidism in 3 young females.
Reactions to amalgam
fillings may contribute to the oral lesions very similar to lichen planus, and a systematic review found that many of the lesions resolved after the fillings were replaced with another material.
Lichen planus can be part of Grinspan's syndrome
.
speciality.
Currently there is no cure for lichen planus but there are certain types of medicines used to reduce the effects of the inflammation. Lichen planus may go into a dormant state after treatment. There are also reports that lichen planus can flare up years after it is considered cured.
Medicines used to treat lichen planus include:
Non-drug treatments:
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
, tongue, and oral mucosa
Oral mucosa
The oral mucosa is the mucous membrane epithelium of the mouth. It can be divided into three categories.*Masticatory mucosa, para-keratinized stratified squamous epithelium, found on the dorsum of the tongue, hard palate and attached gingiva....
. The disease presents itself in the form of papule
Papule
A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm.With regard to the quote "...varying in size from a pinhead to 1cm," depending on which text is referenced, some authors state the cutoff between a papule and a plaque as 0.5cm,...
s, lesion
Lesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s, or rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
es. Lichen planus does not involve lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s, the fungus/algae symbionts that often grow on tree trunks; the name refers to the dry and undulating, "lichen-like" appearance of affected skin. It is sometimes associated with certain medications and diseases, but is basically of unknown cause.
Classification
Lichen planus may be divided into the following types:- Configuration
- Annular lichen planusAnnular lichen planusAnnular lichen planus occurs in approximately ten percent of lichen planus cases, and commonly develop as arcuate groupings of individual papules that develop rings or peripheral extension of clustered papules with central clearing....
- Linear lichen planusLinear lichen planusLinear lichen planus may develop secondary to trauma or, uncommonly, as a spontaneous, isolated eruption, usually on the extremities, and rarely on the face....
- Morphology of lesion
- Hypertrophic lichen planusHypertrophic lichen planusHypertrophic lichen planus usually occurs on the extremities, especially the shin and interphalangeal joints, and tends to be the most pruritic variant of lichen planus....
- Atrophic lichen planusAtrophic lichen planusAtrophic lichen planus is a rare variant of lichen planus, and characterized by the presence of a few well-demarcated, white-bluish papules or plaques with central superficial atrophy....
- Vesiculobullous lichen planus
- Ulcerative lichen planusUlcerative lichen planusUlcerative lichen planus is a rare variant of lichen planus presenting with chronic, painful bullae and ulceration of the feet, often with cicatricial sequelae evident....
- Follicular lichen planus
- Actinic lichen planus
- Lichen planus pigmentosusLichen planus pigmentosusLichen planus pigmentosus is an uncommon variant of lichen planus characterized by hyperpigmented, dark-brown macules in sun-exposed areas and flexural folds....
- Site of involvement
- Lichen planus of the palms and soles (Palmoplantar lichen planus)
- Mucosal lichen planus
- Lichen planus of the nails
- Lichen planus of the scalp ( leading to cicatricial alopecia)
- Inverse lichen planus
- Special forms
- Drug-induced lichen planus
- Lupus erythematosus-lichen planus overlap syndromeLupus erythematosus-lichen planus overlap syndromeLupus erythematosus–lichen planus overlap syndrome is a true overlap syndrome with features of both lupus erythematosus and lichen planus, with skin lesions usually large, atropic, hypopigmented, red or pink patches and plaques.Lichen planus–lupus erythematosus overlap syndrome is a rare variant...
- Lichen planus pemphigoidesLichen planus pemphigoidesLichen planus pemphigoides is characterized by the development of tense blisters atop lesions of lichen planus or the development vesicles de novo on uninvolved skin...
- Keratosis lichenoides chronicaKeratosis lichenoides chronicaKeratosis lichenoides chronica is a rare dermatosis characterized by violaceous papular and nodular lesions, often arranged in a linear or reticulate pattern on the dorsal hands and feet, extremities, and buttock....
- Lichenoid reaction of graft-versus-host diseaseLichenoid reaction of graft-versus-host diseaseLichenoid reaction of graft-versus-host disease presents with chronic graft-versus-host disease, characterized by a lichenoid eruption indistinguishable clinically and histologically from lichen planus. This type of lichenoid lesions have a higher risk of malignant transformation to oral squamous...
- Lichenoid keratosisLichenoid keratosisLichenoid keratoses are a cutaneous condition characterized by brown to red, scaling maculopapules found on sun-exposed skin of extremities...
- Lichenoid dermatitisLichenoid dermatitisLichenoid dermatitis represents a wide range of cutaneous disorders characterized by lichen planus-like skin lesions....
Signs and symptoms
The typical rash of lichen planus is well-described by the "5 Ps": well-defined pruritic, planar, purple, polygonal papules. The commonly affected sites are near the wrist and the ankle. The rash tends to heal with prominent blue-black or brownish discoloration that persists for a long time. Besides the typical lesions, many morphological varieties of the rash may occur. The presence of cutaneous lesions is not constant and may wax and wane over time. Oral lesions tend to last far longer than cutaneous lichen planus lesions.Oral lichen planus (OLP) may present in one of three forms.
- The reticular form is the most common presentation and manifests as white lacy streaks on the mucosa (known as Wickham's striae) or as smaller papules (small raised area). The lesions tend to be bilateral and are asymptomatic. The lacy streaks may also be seen on other parts of the mouth, including the gingiva (gums), the tongue, palate and lips.The reticular form is the easiest to diagnose. The bullas lesions must be differentiated from pemphigoid, chemical burns traumatic ulcers. When they break, they appear as ulcers and need to be differentiated by squamous cell carcinoma.
- The bullous form presents as fluid-filled vesicles which project from the surface.The atrophic and erosive forms must be differentiated from lichenoid drug reactions,SLE, pemphigoids and other immunobullous disease, candidiasis, erythema multiforme.
- The erosive forms (Atrophic LP & Ulcerative LP) present with erythematous (red) areas that are ulcerated and uncomfortable. The erosion of the thin epithelium may occur in multiple areas of the mouth (more prominent on the posterior buccal mucosa), or in one area, such as the gums, where they resemble desquamative gingivitisDesquamative gingivitisDesquamative gingivitis is a cutaneous condition characterized by diffuse gingival erythema with varying degrees of mucosal sloughing and erosion.A band of red atrophic or eroded mucosa affecting the attached gingiva is known as dequamative gingivitis...
. Wickham's striae may also be seen near these ulcerated areas. This form may undergo malignant transformation, although this is controversial. The malignant transformation rate is thought to be less than 1%, however it has been reported to be as high as 5%. For any persistent oral lesion of erosive lichen planus that does not respond to topical corticosteroids, a biopsy is recommended to rule out precancerous (premalignant) change or malignant transformation.
The microscopic appearance of lichen planus is pathognomonic for the condition
- Hyperparakeratosis with thickening of the granular cell layer
- Development of a "saw-tooth" appearance of the rete pegs
- Degeneration of the basal cell layer with Civatte or colloid body formation. These result from degenerating epithelial cells.
- Infiltration of lymphocytic inflammatoryInflammationInflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
cellsWhite blood cellWhite blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
into the subepithelial layer of connective tissue - epithelial connective tissue interphase weakens resulting in formation of histological cleft known as Max. Joseph's space.
Lichen planus may also affect the genital mucosa – vulvovaginal-gingival lichen planus. It can resemble other skin conditions such as atopic dermatitis
Atopic dermatitis
Atopic dermatitis is an inflammatory, chronically relapsing, non-contagious and pruritic skin disorder...
and psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
.
Rarely, lichen planus shows esophageal involvement, where it can present with erosive esophagitis and stricturing. It has also been hypothesized that it is a precursor to squamous cell carcinoma of the esophagus.
Clinical experience suggests that Lichen planus of the skin alone is easier to treat as compared to one which is associated with oral and genital lesions.
Nail & hair loss is irreversible.
Cause
The cause of lichen planus is not known. It is not contagiousContagious disease
A contagious disease is a subset category of infectious diseases , which are easily transmitted by physical contact with the person suffering the disease, or by their secretions or objects touched by them....
and does not involve any known pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
. Some lichen planus-type rashes (known as lichenoid reactions) occur as allergic reactions to medications for high blood pressure, heart disease
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
and arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
, in such cases termed drug-induced lichenoid reaction
Drug-induced lichenoid reaction
Drug-induced lichenoid reactions are skin eruptions that occur after ingestion, contact, or inhalation of certain chemicals, with the most common inducers being gold salts, beta blockers, antimalarials, thiazide diuretics, furosemide, spironolactone, and penicillamine...
s. These lichenoid reactions are referred to as lichenoid mucositis (of the mucosa) or dermatitis (of the skin). Lichen planus has been reported as a complication of chronic hepatitis C
Hepatitis C
Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...
virus infection and can be a sign of chronic graft-versus-host disease
Graft-versus-host disease
Graft-versus-host disease is a common complication after a stem cell transplant or bone marrow transplant from another person . Immune cells in the donated marrow or stem cells recognize the recipient as "foreign". The transplanted immune cells then attack the host's body cells...
of the skin (Lichenoid reaction of graft-versus-host disease
Lichenoid reaction of graft-versus-host disease
Lichenoid reaction of graft-versus-host disease presents with chronic graft-versus-host disease, characterized by a lichenoid eruption indistinguishable clinically and histologically from lichen planus. This type of lichenoid lesions have a higher risk of malignant transformation to oral squamous...
). . It has been suggested that true lichen planus may respond to stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
, where lesions may present on the mucosa or skin during times of stress in those with the disease. Lichen planus affects women more than men (at a ratio of 3:2), and occurs most often in middle-aged adults. The involvement of the mucous membranes is seen frequently and usually is asymptomatic, but occasionally, LP can be complicated by extensive painful erosions. Lichen planus in children is rare. In unpublished clinical observation, lichen planus appears to be associated with hypothyroidism in 3 young females.
Reactions to amalgam
Amalgam (dentistry)
Amalgam is an alloy containing mercury. The term is commonly used for the amalgam employed as material for dental fillings, which consists of mercury , silver , tin , copper , and other trace metals...
fillings may contribute to the oral lesions very similar to lichen planus, and a systematic review found that many of the lesions resolved after the fillings were replaced with another material.
Lichen planus can be part of Grinspan's syndrome
Grinspan's syndrome
Grinspan syndrome is a syndrome characterized by presence of the triad : essential hypertension , diabetes mellitus & oral lichen planus.Oral lichen planus is thought to be a result of the drugs used for treatment of hypertension & diabetes mellitus but this is not confirmed....
.
Treatment
Care of OLP is within the scope of oral medicineOral medicine
Oral medicine is the dental specialty placed at the interface between medicine and dentistry.- Scope :Oral medicine is concerned with diagnosis and non-surgical management of non-dental pathology affecting the oral and maxillofacial region, such as oral lichen planus, Behçet's disease and pemphigus...
speciality.
Currently there is no cure for lichen planus but there are certain types of medicines used to reduce the effects of the inflammation. Lichen planus may go into a dormant state after treatment. There are also reports that lichen planus can flare up years after it is considered cured.
Medicines used to treat lichen planus include:
- Oral and topicalTopicalIn medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
steroids. - Oral retinoids
- immunosuppressantImmunosuppressantAn immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...
medications - hydroxychloroquineHydroxychloroquineHydroxychloroquine is an antimalarial drug, sold under the trade names Plaquenil,Axemal, Dolquine, and Quensyl, also used to reduce inflammation in the treatment of rheumatoid arthritis and lupus...
- tacrolimusTacrolimusTacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection...
- dapsoneDapsoneDapsone is a medication most commonly used in combination with rifampicin and clofazimine as multidrug therapy for the treatment of Mycobacterium leprae infections . It is also second-line treatment for prophylaxis against Pneumocystis pneumonia caused by Pneumocystis jiroveci Dapsone...
Non-drug treatments:
- UVB NarrowBand Phototherapy
- Aloe veraAloe veraAloe vera, pronounced , also known as the true aloe or medicinal aloe, is a species of succulent plant in the genus Aloe that is believed to have originated in the Sudan. Aloe vera grows in arid climates and is widely distributed in Africa, India, Nepal and other arid areas.The species is...
- Purslane