Lichen planus pigmentosus (LPP) is a rare skin condition that causes dark patches of discoloration on the skin. It is caused by an overproduction of melanin, the pigment that gives skin its color. The patches of discoloration can range in color from light brown to and usually appear on the arms, legs, and trunk. LPP is not contagious and is not caused by an infection. Treatment for LPP is usually not necessary, but in some cases, topical medications or laser treatments may be used to lighten the patches of discoloration.

The most common symptoms of Lichen planus pigmentosus (LPP) include:

-Dark, flat patches of skin on the face, neck, arms, and legs
-Itching or Burning sensation on the affected areas
-Raised, scaly, or rough patches of skin
-Discoloration of the skin
-Thickening of the skin
-Hyperpigmentation (darkening of the skin)
-Hypopigmentation (lightening of the skin)
-Scarring of the affected areas

The exact cause of lichen planus pigmentosus is unknown. However, it is believed to be an autoimmune disorder, meaning that the body’s immune system mistakenly attacks healthy cells. Other possible causes include certain medications, infections, and exposure to certain chemicals.

1. Topical corticosteroids: These are the most commonly prescribed treatment for lichen planus pigmentosus. They can help reduce inflammation and itching.

2. Phototherapy: This involves exposing the affected area to ultraviolet light. This can help reduce the appearance of the discoloration.

3. Oral medications: These can include antihistamines, antibiotics, and antifungal medications.

4. Laser therapy: This can help reduce the appearance of the discoloration.

5. Cryotherapy: This involves freezing the affected area with liquid nitrogen. This can help reduce the appearance of the discoloration.

6. Dermabrasion: This involves using a rotating brush to remove the top layer of skin. This can help reduce the appearance of the discoloration.

1. Exposure to certain medications, such as antimalarials, nonsteroidal anti-inflammatory drugs, and certain antibiotics.

2. Exposure to certain chemicals, such as hair dyes, perfumes, and certain metals.

3. Exposure to certain environmental factors, such as ultraviolet light, radiation, and certain pollutants.

4. Genetic predisposition.

5. Stress.

6. Autoimmune disorders, such as lupus and psoriasis.

7. Infections, such as hepatitis C and HIV.

There is no cure for lichen planus pigmentosus, but there are medications that can help manage the symptoms. These include topical corticosteroids, topical calcineurin inhibitors, and oral medications such as hydroxychloroquine and methotrexate. Additionally, phototherapy and laser treatments may be used to reduce the appearance of the discolored patches.