What is Lichen Planus Pigmentosus?

LPP is a rare type of lichen planus. Lichen Planus Pigmentosus is a condition in which there is the presence of asymptomatic slaty-grey flakes which are persistently present mainly on the face and sun-exposed areas. The pattern presented in it is mostly actinic in which pigmentation is diffuse and symmetrical. It is known to be a variant of cutaneous Lichen planus in which flexural and sun-exposed areas of the body are affected.

What is the prevalence of LPP?

Lichen planus pigmentosus (LPP) is considered a rare condition, and its exact prevalence is not well-established in the general population. However, it is more commonly reported in certain regions and populations.

Geographic Variability: It has a higher prevalence in regions with more sun exposure, such as in countries of the Middle East, South Asia, and Latin America. It’s notably more common in India and other parts of South Asia, where studies have shown a higher frequency of cases.

Age and Gender: The condition can affect individuals of any age but is typically seen in adults, with a peak occurrence in the middle-aged group (30-50 years). There is a slight female predominance in many cases, although both genders can be affected.

Skin Type: LPP tends to affect individuals with darker skin types making it more prevalent among people with darker complexions.

Is Lichen Planus Pigmentosus an autoimmune disorder?

Yes, lichen planus pigmentosus is considered an autoimmune-related condition where the immune system mistakenly attacks the body’s own tissues. In the case of LPP:

The immune system appears to target and damage the skin cells, leading to the characteristic inflammation and hyperpigmentation that define the condition.

T cells, which are a type of white blood cell involved in immune responses, have been implicated in the inflammatory process seen in LPP. They likely play a role in damaging the skin and causing the discoloration of affected areas.

Although LPP shares some features with other forms of lichen planus, which is also thought to have an autoimmune origin, LPP specifically causes pigmentation changes and primarily affects people with darker skin types.

What are the causes of Lichen Planus Pigmentosus?

There is not a particularly known etiology, but some trigger factors can contribute to its development:

• Genetics: A family history of this may increase the risk of developing this condition.
• Sun exposure: Ultraviolet (UV) light from the sun is thought to be a significant environmental trigger for LPP. In people with a predisposition to the condition, sun exposure may provoke the inflammatory response that leads to the development of darkened patches of skin.
• Immune response: This means that the body’s immune system mistakenly attacks its own skin cells. In the case of LPP, T cells, seem to target and damage the skin cells, leading to inflammation and the characteristic pigmentation changes.
• Viral infections: Lichen planus, including its pigmentosus variant, has been associated with hepatitis C infection. Chronic viral infections can trigger autoimmune responses that affect the skin.
• Hormonal Changes : Hormonal fluctuations may contribute to the development or worsening of autoimmune diseases, including skin conditions like LPP. This is why LPP is more frequently seen in adults and often in women.
• Environmental factors: exposure to certain chemicals or allergens (such as those found in cosmetics, perfumes, or dyes) could potentially trigger or worsen LPP.
• Skin injury: It may develop or worsen following skin trauma which means that skin injury or irritation (like scratching, cuts, or sunburn) can lead to the formation of LPP lesions in the affected area.

What are the symptoms of Lichen Planus Pigmentosus ?

The symptoms of Lichen Planus Pigmentosus (LPP) can vary from person to person, but generally, the condition is relatively mild in terms of discomfort. It is usually a disease in the third and fourth decade of life and the symptoms of the lesions include:

    1. Pigmented patches or spots:

• Color: The patches are typically brown, gray, or dark purple.
• Location: These patches usually appear on sun-exposed areas like the face, neck, upper chest, and forearms. They can also appear in other areas, but it’s more common in sun-exposed regions.
• Texture: The skin in the affected areas may appear slightly darker than surrounding skin, and the patches can sometimes have a slightly rough or velvety texture.

2. Asymptomatic:

• LPP often doesn’t cause itching or pain, which differentiates it from other forms of lichen planus that may be itchy.
• There may be mild discomfort or irritation in some cases, but this is less common.

   3. Hyperpigmentation:

• The skin affected by LPP tends to darken over time, and the dark spots or patches can persist for months or years.
• It may take months after the condition starts for the pigmentation to become noticeable.

  4. No Skin Ulcers or Bumps:

• Unlike typical lichen planus, LPP does not usually present with the raised, purple, itchy bumps or ulcers found in other types of lichen planus.

  5. Potential for Scarring:

• Although it is uncommon, prolonged pigmentation changes or improper treatment can lead to scarring in some cases.

How does LPP develop?

LPP occurs when the CD8+ autoreactive T cells start attacking epidermal keratinocytes, leading to an inflammatory lichenoid response. As a result, the initial inflammatory infiltrate gets resolved quickly and leaves behind marked dermal pigmentary incontinence.

What are the commonly affected areas in lichen planus?

Commonly affected areas include:

• Face.

• Neck

• Upper limbs:
• Axillae
• Groin

LPP is often associated with hyperpigmented patches that may appear gradually, and these patches tend to darken over time. Since sun exposure can exacerbate LPP, using sunscreen and protecting exposed skin areas is crucial for managing the condition.

What is the appearance of lesions of Lichen Planus Pigmentosus?

Initially, the lesions are oval macules which are small, and black with diffuse borders and later these merge into grey-brown pigmented areas. The patches of LPP look symmetrical and are found in different patterns like blaschkoid, zosteriform or segmental pattern.

How does LPP occur?

Occurs mainly in isolation and in only 20% of cases it occurs along with the following conditions:

• Frontal fibrosing alopecia
• Oral LP
• Classic LP
• Lichen planopilaris

Also Read: Lichen Simplex Chronicus/ Neurodermatitis

What are the diseases that can be associated with LPP?

Lichen planus pigmentosus (LPP) can be associated with several conditions, either as a comorbidity or a trigger. Some of the diseases and factors that can be linked with LPP include:

Metabolic Syndrome

• Lichen planus pigmentosus has been observed more frequently in individuals with metabolic syndrome which includes condition such as obesity, hypertension, insulin resistance, and dyslipidemia (abnormal cholesterol levels).
• Type 2 Diabetes

• The chronic inflammation linked to diabetes could potentially trigger or exacerbate LPP.

Thyroid Disorders

• The immune dysfunction associated with thyroid diseases could be a contributing factor to the development of LPP.

Drug Reactions

• Drugs such as antihypertensive medications (e.g., ACE inhibitors), nonsteroidal anti-inflammatory drugs (NSAIDs), and others may act as triggers for LPP.

Autoimmune Disorders

• LPP has been observed in some patients with autoimmune conditions such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and others. In these diseases, the body’s immune system mistakenly attacks its own tissues, which could trigger skin disorders like LPP.

Stress

• Though not a disease, prolonged stress and psychological factors have been identified as potential triggers for various autoimmune skin conditions, including LPP.

Nutritional Deficiencies

• Certain nutritional deficiencies, especially vitamin B12 and folate, may contribute to the development of skin disorders, though a direct link to LPP is still under study.

Hormonal Changes

• Hormonal fluctuations, such as those occurring in pregnancy, menopause, or due to hormonal therapies, could also be a contributing factor, although the exact role of hormones in the development of LPP is not completely clear.

Is LPP contagious?

No, lichen planus pigmentosus (LPP) is not contagious. It is a non-infectious condition, meaning it cannot be spread through physical contact, touching, or sharing items like towels or clothes.

LPP is believed to be an autoimmune response, where the body’s immune system mistakenly attacks its own skin cells. The exact cause is not fully understood, but it’s typically triggered by factors like genetics, medications, or environmental triggers, rather than infection from another person.

Also Read: LICHEN PLANUS TREATED SUCCESSFULLY BY HOMEOPATHY

What is the differential diagnosis of LPP?

• Ashy dermatosis
• Lichenoid drug eruption
• Maturational hyperpigmentation
• Melasma
• Macular amyloidosis
• Fixed drug eruption
• Pigmented contact dermatitis
• Idiopathic eruptive macular pigmentation
• Actinic lichen planus
• Acanthosis nigricans
• Linear psoriasis
• Linear lichen planus

How can be this condition diagnosed?

Diagnosing LPP involves a combination of clinical evaluation, patient history, and sometimes skin biopsy. Here’s how it is typically diagnosed:

Clinical Examination: LPP typically presents as hyperpigmented, asymptomatic patches or macules, often with irregular borders.

Patient History: The patient may have a history of chronic skin conditions, or sometimes, LPP may develop after exposure to drugs, infections, or even certain environmental factors.

Skin Biopsy: A skin biopsy can help confirm the diagnosis.

What is the prognosis of Lichen Planus Pigmentosus?

The course and prognosis of the disease are variable as the pigmentation may resolve spontaneously or last from a few weeks to months. The course of LPP is also unpredictable.

The main concerns are the long-term persistence of pigmentation and the potential impact on appearance.

What is the general management for Lichen Planus Pigmentosus?

The general management of lichen planus pigmentosus  focuses on controlling inflammation, improving the appearance of pigmented lesions, and preventing flare-ups.

It can be effectively managed in the following ways:

• Skin care-

Keeping the skin moisturized can help reduce irritation and prevent further damage, as dry skin can worsen pigmentation.

Use gentle, fragrance-free cleansers and moisturizers to protect the skin.

Sunscreen is crucial since sun exposure can worsen pigmentation and trigger flare-ups. Use a broad-spectrum sunscreen with high SPF.

• Avoid triggers-

Certain medications (like NSAIDs or some antihypertensive drugs).

Skin trauma (including scratching, cuts, or burns).

Stress or other environmental factors.

Avoid sun exposure or use sun protection if the skin is exposed to sunlight.

How is LPP managed homeopathically?

Following homoeopathic medicines can help treat Lichen Planus Pigmentosus:

• Antimonium crudum: It is the best remedy for LPP where the skin looks dry with intense itching. Eruptions are measles-like and itching and burning on these is worse from the heat of bed. Gastric derangements are present along with this. Skin presents with thick, hard scabs, often honey-yellow with a crack oozing a green sanious fluid and burning as if immersed in hot embers.
• Thuja: This medicine is most suited where hyperpigmented eruptions are brown-coloured and present mostly on the face, hands and arms, this medicine is considered effective. Violent itching is presented which gets better by cold bathing. Patient has a tendency to develop  Eruptions only on covered parts which are worse after scratching.
• Sulphur Iodatum: Patients which have papular eruptions present with intense itching specially on the ears and neck. Obstinate skin affections specially affecting arms that are covered with an itching rash. Patient presents with boils on neck and sensation as if hair are erected.
• Arsenic album: The skin eruptions are burning, and the patient is extremely restless and anxious. Papular, dry eruptions which are worse from itching and cold are present.With these skin symptoms patient presents with prevailing debility, exhaustion, and restlessness. All the symptoms show nightly aggravation.
• Lachesis: This medicines works well where skin appears blue, and black in appearance and eruptions look bluish. Tight clothing is unbearable around the neck, abdomen and head. Rashes may appear in patches and are often worse on the left side of the body. In some cases induration and thickening of skin are commonly noticed.

Disclaimer: The information provided is for educational purposes only and should not be construed as medical advice. Always consult a qualified healthcare professional or physician before starting any treatment or using any medication. Self-medication without professional guidance can be harmful to your health. The content provided here is not intended to replace professional medical advice, diagnosis, or treatment.