Oral Medicine & Pathology

Lichen Planus: Causes, Symptoms, Diagnosis and treatment

Lichen planus is an inflammatory, non-infectious disease that can affect skin, nails, hair, and mucous membranes. It consists of a rash of bumps causes itchy or burning sensations in the affected areas. Recent studies showed that it affects around 1% of the population. 

Lichen Planus Treatment, Causes, Signs and symptoms

Etiology of Lichen Planus:

Although the exact causes of lichen planus is unknown, it’s believed that multiple factors exaggerate and trigger it: 

  1. Autoimmune response: many types of researches see that the main cause of the lichen planus is the autoimmune response of the immunity system. It starts to attack the cells of the skin and mucous membranes by mistake, leading to inflammation of the attacked sites, and then the appearance of these lesions.
  2. Reaction to drugs: Certain drugs may trigger lichen planus to happen, such as blood pressure, diabetes, arthritis, malaria drugs, and NSAIDs (Non-steroidal anti-inflammatory drugs). In addition, drugs that contain arsenic, bismuth, or gold hold the risk to produce lesions typical to lichen planus.
  3. Dental materials: Some materials that dentists use in their daily work may trigger oral lichen planus, such as Amalgam metallic filling. Prolonged use of a denture may also cause LP.
  4. Hepatitis C Virus: patients infected with the hepatitis C virus have the risk to develop lichen planus lesions.
  5. Genetic background.

Signs and Symptoms of Lichen Planus: 

Lichen planus appears in many sites in the body:

1. Skin Signs & Symptoms:

  • Lichen planus of the skin is characterized by the 5p (Purple, polygonal, pruritic, papules, and plaque). 
  • The most common sites for these lesions to be observed are the back, ankles, arms, and wrists. 
  • Purple or bright red raised bumps may be little or severe itch. 
  • These bumps may be accompanied by white strikes called Wickham’s striae.
  • They may be few or many bumps.
  • Hypertrophic lichen planus lesions sometimes affect the shines
  • After the disappearance of the lesions, it may leave a permanent discoloration in the skin.
Is lichen planus a contagious disease?
Lichen planus is not contiguous, so it doesn’t spread from one person to another one
Skin Manifestations
Skin Manifestations - Flexor and legs - papular

2. Oral Lichen Planus Signs & Symptoms

          Lesions may show a variety of clinical forms:

  • White raised dots or striae which knows as “Wickham striae” on the cheeks or the tongue, they are completely asymptomatic (Reticular pattern). 
  • When the lesions start to be symptomatic, this is because of the erosion that happened to them, this pattern characterized by white keratinized lines surrounding the main lesion (Erosive pattern).
  • Sometimes oral lichen planus may exhibit a mix of 2 clinical forms, as it may be white lesions surrounded by erythematous area (Atrophic pattern).
  • Another clinical form can be found, where the lesions are seen as white irregular lesions and can be mistaken as leukoplakia.
  • The papular clinical form is rarely observed, but if it’s found, it will be followed by another clinical form of those who have been mentioned. It appears as white papules surrounded by white lines.

The lesions are bilateral and symmetrical and may appear on any site in the oral cavity, but the most common sites are buccal mucosa, tongue, and gingiva. Mild cases don’t cause any symptoms, while in severe cases, there are sore ulcers causing discomfort while eating.

The gingiva may be involved, showing atrophic or erosive patterns (Desquamative Gingivitis).

Oral Manifestation of Lichen Planus
Erosive Lichen planus surrounded by erythematous area with Wickham striae
Atrophic pattern of LP

3. Nails Signs & Symptoms:

They may become thinner/thicker, grooved, separated, or lost.

The effect on nails

4. Scalp Signs & Symptoms:

Appears as red patches on the scalp, in some cases, permanent hair loss may occur resulting in areas of no hair.

Permanent hair loss may occur

5. Genitals Signs & Symptoms:

Genitals also show some signs and symptoms

Lichen planus is observed in the middle age, it doesn’t affect the children or the geriatric people. It affects women twice than men.

Diagnosis of Lichen Planus

The doctor or the dentist suspects lichen planus by medical history, patient complaint, and the rash. But the diagnosis can not be confirmed without taking a biopsy and sending it to the laboratory to be examined under the microscope. The characteristic histological features of lichen planus are hydropic degeneration of the basal layer, lymphocytic infiltration in the sub-epithelial layer, and the absence of epithelial dysplasia.

Diagnosis Chart

Complications of Lichen Planus

  • The long-lasting clinical form of the lichen planus may develop into cancer. So be aware of the ulcers that stand for a long time without healing.
  • Discoloration of the skin, thus, scratching the skin should be avoided.
  • Permanent loss of hair may occur if the LP affects the scalp.

Management and Treatment

What is the best treatment for lichen planus?

There’s no known cure for lichen planus till the day of this article, but all the treatment and management methods aim to relieve the symptoms. So in the case of mild asymptomatic lesions, there is no need for any treatment as it resolves by itself in a few weeks or months.

For symptomatic cases and those which cause discomfort, the doctor/dentist may prescribe some medications. Besides, give instructions to the patient about lifestyle modifications to prevent further complications and worsen. 

Prescribed medications may be

  1. Corticosteroids: They are used to relieve the symptoms by reduction of the inflammation, redness, and itching sensation. They can be used topically such as corticosteroid creams (clobetasol propionate) and ointments, or oral tablets. The tablets used when the topical methods aren’t effective to treat severe cases. In the case of oral lichen planus, Corticosteroids gels/sprays or mouth wash can be prescribed. Like any other drug, Corticosteroids have side effects like:
    • Insomnia
    • Weight gain
    • Increased appetite 
    • Mood switch such as feeling anxious and irritable.
  2. Topical Non-steroidal creams can be applied to the affected sites.
  3. Anti-histamines: used to relieve the allergy symptoms that appear like the itchy and burning sensation, and also where the rash is triggered by an antigen. 
  4. Retinoid: can be taken orally or topically.
  5. Anti-septic Mouthwashes can be prescribed also for oral LP to prevent the accumulation of plaque as plaque complicates the condition. Other types of mouthwashes containing anesthetic solutions help to numb the mouth to make the chewing easier and free of pain.
Erosive Lichen Planus treatment according to case severity

The doctor/dentist should also give the patients instructions about changing their lifestyle to prevent further the complications, which include: 

  1. Avoid washing the affected skin by soap; using warm running water is better.
  2. Never scratch the lesion.
  3. Applying a cool compress to the rash.
  4. Stop smoking and drinking alcohol.
  5. Eating non-spicy food to prevent the irritation of the lesion site.

Finally, you have to visit your doctor/ dentist regularly to check up if you have any risk factors to develop LP.