Lichen planus pilaris (LPP) is a form of skin disorder which, although relatively unknown, has a significant impact on the quality of life of sufferers. Characterised by persistent inflammation of the scalp, this autoimmune disease causes scarring alopecia, leading to irreversible hair loss in the affected areas. Find out all you need to know about this disease and its treatment options.
What is lichen planus pilaris?
Lichen planus pilaris is a chronic inflammatory disease of the scalp. This is a specific form of lichen planus that mainly affects the hair follicles, which can lead to scarring alopecia, i.e. hair loss with scarring, making the loss irreversible.
" Scarring alopecia " refers to a set of scalp pathologies leading to hair loss accompanied by fibrosis of the area concerned, resulting in a permanent absence of hair in that area. Lichen is often the cause of this type of alopecia. It is crucial to identify these alopecias at an early stage in order to try to halt the progression of the disease and avoid permanent scarring of the hair.
What are the different clinical forms of lichen planus pilaris?
Lichen planus encompasses several clinical variants, two of the best known being alopecia frontalis fibrosa (AFF) and Graham-Little-Piccardi-Lasseur (GLPL) syndrome:
- Fibrosing frontal alopecia: this form of progressive scarring alopecia is characterised by linear hair loss along the anterior line of the scalp and sometimes also the eyebrows.
- Graham-Little-Piccardi-Lasseur syndrome: this rare variant of LPP is characterised by a combination of scarring hair loss of the scalp, non-scarring alopecia of the armpits and pubis, and the presence of keratotic papules (small rough bumps) on the trunk and limbs.
What are the symptoms of lichen planus pilaris?
Symptoms of lichen planus pilaris may vary from person to person, but they generally include one or more of the following manifestations:
- Progressive hair loss: hair loss is generally gradual, and often occurs in specific areas of the scalp.
- Papules: small pimples or lesions may form, usually around the hair follicles. These papules may be red or purple in colour and sometimes have a scaly appearance.
- Itching: sufferers may experience itching of the scalp, which can sometimes be intense.
- Pain and burning sensation: a sensation of pain or burning may be present in the affected areas of the scalp.
- Healing: over time, the affected areas may show signs of scarring, with a whitish appearance or a change in the texture of the skin. This scarring can lead to irreversible hair loss in the affected area.
- Hyperpigmentation or hypopigmentation: in some cases, changes in skin pigmentation may be observed in the affected areas.
- Changes to the nails: although less common, LPP can also be associated with changes to the nails, such as streaks or lines.
- Rashes on the skin: in some cases, rashes may also appear on other parts of the body, although this is more characteristic of classic lichen planus.
What causes lichen planus pilaris?
The precise cause of lichen planus pilaris remains a mystery, although it is neither hereditary nor transmissible. It is often linked to an immune system imbalance, as evidenced by the T lymphocytes and antibodies seen around the affected hair follicles. Intense emotional events, certain medications and conditions such as diabetes, hypertension, hepatitis C and colitis can act as triggers.
How is lichen planus pilaris diagnosed?
The diagnosis of lichen planus pilaris is based on a combination of clinical features, physical examinations and specialised tests.
On initial examination, a dermatologist will look for characteristic symptoms, such as hair loss, papules, and the specific scarring appearance of the scalp. For a more in-depth analysis, dermatoscopy, which uses a pocket microscope, can reveal details such as perifolliculitis and other changes in the follicles. However, for definitive confirmation, a scalp biopsy is often necessary.
Blood tests may be carried out to rule out other pathologies or detect associated conditions. Finally, it is crucial to gather information about the patient's medical and medication history, as well as inspecting the nails and mucous membranes, as LPP can sometimes present symptoms in these areas.
What diseases can lichen planus be confused with?
Lichen planus pilaris can present symptoms similar to several other scalp conditions, which can sometimes complicate its diagnosis. Among the diseases that can be confused with LPP are :
- Alopecia areata alopecia areata is a condition that causes hair to fall out, often in small, rounded patches. Most people with alopecia areata will experience hair regrowth within a few months to a year, even without treatment. However, the condition can recur and, in some cases, hair loss can be permanent.
- Discoid lupus erythematosus: this form of lupus mainly affects the skin and can cause scarring of the scalp.
- Decalcifying folliculitis: this is another form of scarring alopecia resulting from inflammation and destruction of the hair follicles. It may resemble LPP but has its own distinctive features.
Early diagnosis of lichen planus pilaris is crucial for several reasons. LPP is a form of scarring alopecia. This means that hair follicles are replaced by scar tissue as the disease progresses. Once a follicle is destroyed, it is impossible for hair to grow back in that area. Early diagnosis means that treatment can be initiated quickly, reducing the risk of permanent damage.
How is lichen planus treated?
The main aims of lichen planus treatment are to stop or slow the progression of the disease, reduce inflammation and prevent further hair loss.
Topical corticosteroids applied directly to the scalp are often the first line of treatment. These drugs aim to reduce inflammation. For particularly resistant or inflamed areas, corticosteroid injections can be used to directly target the inflammation around the hair follicles. In addition, hydroxychloroquine, an anti-malarial drug, is sometimes prescribed, particularly for more severe or refractory forms of LPP.
It is crucial to understand that lichen planus pilaris is a complex disease. Response to treatment varies from patient to patient. An individualised approach and close communication with a hair specialist are essential to achieve the best possible results. Also, the earlier LPP is diagnosed, the better the chances of success with available treatments. While some treatments may not be effective in the advanced stages, they can offer significant benefits when applied early.
Can scarring caused by lichen planus pilaris be treated?
Unfortunately, scarring caused by lichen planus pilaris is permanent. The inflammation irreversibly destroys the hair follicles, making it impossible for them to regenerate. However, thanks to advances in reconstructive surgery and hair transplants, it is possible, depending on the situation, to minimise the appearance of scars or camouflage bald spots.
Jean-François Cabos is the creator of a unique hair care method based on the research he coordinated, which led to the publication of the book Hair, Roots of Life with Hélène Clauderer published by Robert Laffont (Collection "Réponses/ Santé").
