Scarring alopecia is a form of alopecia that results from the permanent destruction of hair follicles. This form of baldness differs from other types of alopecia because of the permanent nature of hair loss. How does it happen? What causes it and how can you recognise it? Find out all you need to know about scarring alopecia.
Scarring alopecia : definition
Scarring alopecia is a form of hair loss characterised by the irreversible destruction of hair follicles.These are replaced by scar tissue. Unlike other types of alopecia where hair regrowth is possible, in the case of scarring alopecia, the destruction of the follicles prevents any regrowth, leading to permanent baldness in the affected areas.
What causes scarring alopecia?
Several causes can be the cause of scarring alopecia:
- Infections: certain infectious agents, such as bacteria, fungi or viruses, can attack the scalp and hair follicles, causing scarring. Examples include tinea capitis, bacterial folliculitis and some forms of syphilis.
- Autoimmune diseases: in conditions such as discoid lupus erythematosus and lichen planopilaris, the immune system mistakenly attacks the hair follicles, causing inflammation and scarring.
- Trauma: physical injuries, such as burns, cuts or surgery, can damage the scalp and lead to scarring alopecia.
- Skin tumours: some tumours, benign or malignant, can destroy the hair follicles. These include tumours such as basal cell carcinoma or squamous cell carcinoma.
- Certain inflammatory conditions: cellulitis dissecans and folliculitis decalvans are inflammatory conditions that cause scarring and hair loss. In both cases, the intense inflammation of the scalp leads to the destruction of the hair follicle making it impossible to regrow hair in the affected areas.
- Chemical agents: exposure to certain chemicals, particularly those used in aggressive hair treatments, can burn and damage the scalp, leading to scarring alopecia.
- Radiotherapy: people receiving radiotherapy on the scalp to treat cancer may develop scarring alopecia in the area of exposure.
- Certain rare genetic diseases: certain hereditary conditions can lead to scarring alopecia.
What are the symptoms of scarring alopecia?
Scarring alopecia, resulting from the destruction of hair follicles and their replacement by scar tissue, is manifested by several characteristic symptoms.
The areas affected show progressive hair loss, often irregular. These areas may spread slowly over time. The scalp in areas of alopecia often has a shiny, smooth, poreless appearance, a sign of the presence of scar tissue. Many people report itching in the affected areas, although the intensity may vary. A burning sensation can also precede, accompany or follow hair loss.
In some forms of scarring alopecia, such as decalcifying folliculitis, inflammatory pustules or pimples may appear around the hair follicles.
In the case of lichen planus pilaris, the lesion may not cause any symptoms or, on the contrary, may be inflamed, causing discomfort or itching. It is not unusual to observe small scales around areas of alopecia.
As for the specific variant fibrosing frontal alopecia, hair loss mainly affects the edge of the scalp and can also lead to hair loss around the eyebrows.
In chronic lupus erythematosus, hair loss is just one of many potential symptoms. This autoimmune condition can affect the joints, causing joint pain. It can also target the heart and lungs, causing chest pain or episodes of coughing. Lupus can also affect the kidney and other internal organs.
Unlike other types of alopecia, hair growth is absent in scarred areas because the hair follicles have been irreparably destroyed.
Who can suffer from scarring alopecia?
Scarring alopecia can affect anyone, regardless of age, sex or ethnic origin. Although it can occur at any age, some forms of scarring alopecia are more common at specific stages of life. For example, frontal fibrosing alopecia is more common in post-menopausal women.
How is scarring alopecia diagnosed?
To diagnose scarring alopecia, a thorough clinical assessment and can involve several methods and examinations. First and foremost, it is based on meticulous observation of the lesions during a clinical examination, often assisted by a dermatoscope. However, it is mainly the biopsy, a skin sample taken under local anaesthetic, that confirms the diagnosis and identifies the underlying cause of the alopecia.
If pustules are visible, a sample will be taken for microbiological examination, to detect any bacteria or fungi. In particular, in the case of previously undiagnosed chronic lupus erythematosus, an immunological examination will be required.
Determining the exact cause of scarring alopecia can be complex. Additional tests are sometimes essential to differentiate between different aetiologies.
How is scarring alopecia treated?
The treatments available for scarring alopecia vary according to the origin of the condition. Whatever the cause, the aim of medication is to prevent the appearance of new areas of inflammation devoid of hair and, if possible, to slow the progression of the disease.
There are various medicinal approaches to treating scarring alopecia, including :
- Antibiotics: these drugs are used to treat or prevent bacterial infection. They are particularly useful for conditions such as dissecting cellulitis, decalcifying folliculitis, erosive pustulosis or alopeciating nodules.
- Corticoids or dermocorticoids: thanks to their anti-inflammatory and immunosuppressive properties, these drugs have proved effective for conditions such as chronic lupus erythematosus, lichen planus pilaris and erosive pustulosis.
- Synthetic antimalarials: although originally developed to treat malaria, these drugs can also be beneficial for conditions such as lupus or lichen planus pilaris.
- Immunosuppressants: designed to modulate or inhibit the activity of the immune system, they are used in the treatment of autoimmune diseases to stop the inappropriate immune attack.
The choice of treatment depends on the underlying cause of scarring alopecia. The success of treatment can vary. Regular care and follow-up are essential to achieve the best possible results.
What other conditions might scarring alopecia be confused with?
Scarring alopecia has characteristics that can sometimes be similar to those of other conditions, leading to confusion. Some of the diseases or conditions with which scarring alopecia can be confused include:
- Androgenetic alopecia: this is the most common form of hair loss in men as in women. Although non-inflammatory, its progression can sometimes be confused with forms of scarring alopecia.
- Alopecia areata: this autoimmune condition causes sudden hair loss in small round or oval patches. Although it is not scarring, hair loss can be similar.
- Ringworm of the scalp: this fungal infection of the scalp can cause bald patches that can be confused with scarring alopecia, particularly in children.
- Dermatoses of the scalp: other inflammatory skin conditions, such as psoriasis or seborrhoeic dermatitis, can cause hair loss, but this is generally reversible.
Because of these possible confusions, it is crucial to consult a hair health professional if you notice any signs of hair loss in order to obtain an accurate and appropriate diagnosis.
Why carry out a Clauderer hair diagnosis?
Not all forms of alopecia are scarring. A hair diagnosis helps to distinguish scarring alopecia from other types of hair loss, facilitating an appropriate approach.
A thorough examination of the scalp will help determine the severity of the condition, the areas specifically affected, and whether other areas could be at risk.
Scarring alopecia can have several underlying causes. Once the specific cause has been identified, suitable treatment may be recommended to halt or slow the progression of the disease. Because it is irreversible, lost hair will not grow back. Early and accurate diagnosis can help prevent further hair loss.
In addition to drug treatments, a Clauderer hair diagnosis offers personalised advice on caring for the scalp, choosing appropriate products and, if necessary, considering beauty solutions.
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").
