lichen planus

Oral lichen planus (OLP) is a common mucocutaneous disease and is thought to affect 0.5-1% of the world's population. This condition can affect either the skin or mucosa or both. It cause bilateral white striations, papules or plaques on the buccal mucosa, tongue, and gingival. Erythema, erosions and blisters may or may not be present.

The relative risk for oral lichen planus is highest among those who smokes and chewes tobacco.

Aetiology:-

It is T-cell mediated auto-immune disease

↓

cytotoxic CD8 + T-cell trigger apoptosis of epithelial cells

↓

recognition of antigen associated with  MHC

 (Major Histocompatibility Complex)

↓

activation of CD8 + T-cell 

↓

trigger keratinocytes apoptosis

↓

activated CD8 + T-cell may release cytokines that attract

additional lymphocytes into developing lesion.

Clinical Features:-

1.) Affects female more (1.4:1).

2.) Probably occurs in older than 40 years.

3.) Skin lesion appears as small, angular, flat-topped, papules only few mm in diameters. 

4.)  Early it appears red, but soon take on reddish purple or violaceous hue.

5.) Later a dirty brownish color develops.

6.) The center of the papules may be slightly umbilicated. It's surface is covered by characteristic very fine grayish-white line is knows as "Wickham's striae".

7.) The lesion may occur anywhere on skin surface but usually are distributed in bilaterally symmetrical pattern, most often on flexor surface of wrist and forearms, the inner aspects of the knees and thighs, face frequently remain un-involved.

8.) Common symptom is PRURITUS.

Oral manifestation:-

The majority of the patient with dermal lesion also associated with oral lichen planus.

If there are only oral lesion, and no lesion on body then it is called "isolated lichen planus".

Clinically it is classified into:-

1.) Reticular 

2.) Atropic

3.) Erosive

4.) Plaque

5.) Bullous

6.) Papuler

1.) Reticular:-

Radiating white/grey, velvety,thread-like papules in angular/reticular form.

Site:- Buccal mucosa & lesser extent to lip, tongue & palate.

2.) Atropic:-

It occurs in a form of  smooth, red, poorly defined areas often but not always with peripheral striae.

3.) Erosive:-

Ulcerated lesion are irregular in size & shape appears painful ulcers.

Site:- Buccal mucosa, tongue, lip, palate.

4.) Plaque:-

Multiple papules are seen.

Site:- Buccal mucosa, dorsum of tongue 

5.) Bullous:-

Resembles erosive when vesicle rupture.

6.) Hypertropic:-

Well circumscribed elevated lesion resembling leukoplakia.

Some oral lesions resemble lichen planus, clinically and histologically but usually have a stimulating or initiating factor, which when removed causes regression of the lesion such oral lesion are termed as Lichenoid reactions.

Histological features:-

1.)Typical histopathologic findings include hyperparakeratosis and hyperorthokeratosis with thickning of Granular layer, acanthosis with intercellular edema of spinous cell.
2.) There is a destruction of basal cells by liquefication degeneration and development of "saw tooth" appearance of rete pegs due to disorganization of basal layer.
3.) subepithelial band of lymphocytic infiltration.
4.) Civatte bodies (eosinophilic apoptotic bodies) seen between epithelium & lamina propria, contain fibrin, IgM, C3, C4, keratin
5.) T-cells seen below cytoplasm.
6.) MAX-JOSEPH SPACES:- Degeneration of basal keratinocytes & disruption of anchoring elements of epithelial basement membrane & basal keratinocytes weakens epithelial connective tissue and forms clefts and blisters.

Malignant trasformation :- 

0.3 %to 3%.1

Most commonly erosive and atropic.

Treatment:-

At present there is no cure, although various agents have been tried. Due to it's minimal malignant transformation, these patient are kept on long term follow ups. As it is autoimmune-mediated condition corticosteroids are recommended.
Patients should be observed periodically, particularly those with history of alcohol and tobacco use, because of the risk of malignant transformation.


You can also watch my video upon Lichen planus:-