Scarring Alopecia: Causes and Treatment
The term Scarring Alopecia is used to describe a group of heterogeneous diseases characterized by the destruction of hair follicles and their replacement with scar tissue.

This destruction results in permanent hair loss.

Scarring forms of hair loss account for approximately 7% of alopecia patients and can appear in otherwise healthy men and women of all ages.

For each individual condition within the category of scarring alopecias, the incidence rate is extremely low.

In most cases, hair loss takes the form of small patches that expand over time. These patches differ from those of alopecia areata by the roughness observed at their edges.

In some cases, scarring alopecia is asymptomatic and progresses gradually, while in others, it advances rapidly and is accompanied by burning sensations, itching, or pain.

Affected areas may show redness, scaling, reduced or increased pigmentation, pustules, or fistulas.

Recent studies suggest that the causes of scarring alopecia are related to irreversible damage to epithelial hair follicle stem cells (eHFSC), located at the “bulge” of the hair follicle.

Depending on the nature of the cause, scarring alopecias can be classified as primary or secondary:

In primary scarring alopecias, the cause is endogenous, with hair follicles destroyed by an inflammatory process.
In secondary scarring alopecias, follicle destruction results from external factors such as trauma, burns, or neoplasms.
Primary Scarring Alopecias
Primary scarring alopecias account for approximately 3.2% of alopecia cases.

Based on the type of cells destroying the hair follicles, they are categorized into:

Lymphocytic
Neutrophilic
Mixed
Diagnosis of Primary Scarring Alopecias
The clinical presentation of the patient can provide clues for diagnosing scarring alopecias. However, to achieve a complete understanding and determine the specific type of the disease, one or more biopsies are performed. These biopsies examine the destruction of hair follicles, the presence of scar tissue deep within the skin, and the potential presence and location of inflammation in relation to the hair follicles.

Treatment of Primary Scarring Alopecias
Given the difficulty in treating scarring alopecias once they have developed, the goal of treatment is to slow down or halt the inflammatory process before it progresses.

Since this type of alopecia can cause significant damage or permanent hair loss, the treatments used are often aggressive. The choice of treatment depends on the diagnosis and includes corticosteroids, antibiotics, antimalarial drugs, and isotretinoin.

In some cases, if hair loss has ceased for several years, surgical treatment may be an option.

Common Causes of Scarring Alopecia
Follicular Lichen Planus
This is the most common cause of scarring alopecia. It primarily occurs in middle-aged individuals (40–60 years old) and is more prevalent in women than in men. It rarely appears in childhood. In 17–50% of cases, it coexists with more common forms of lichen planus.

The cause of follicular lichen planus is unknown, though it is considered an autoimmune disorder.

Clinically, it manifests as bald patches with erythema and perifollicular hyperkeratosis. In some cases, there are no symptoms, while in others, hair loss may be accompanied by itching or discomfort.

Treatment focuses on slowing hair loss and reducing symptoms, mainly through corticosteroids administered orally or topically.

Discoid Lupus Erythematosus (DLE)
This is the second most common cause of scarring alopecia. It is an autoimmune disease of unknown origin that typically manifests between the ages of 20 and 40 and is more prevalent in women. In 5% of cases, it progresses to systemic lupus erythematosus.

Clinically, it presents as discoid, erythematous plaques with follicular plugging and hypo- or hyperpigmentation, atrophy, and telangiectasia.

Treatment includes protection from sunlight, along with hydroxychloroquine, topical and systemic steroids, minoxidil, and immunosuppressive drugs.