In active scarring alopecia, inflammation is often concentrated around hair follicles and can damage the structures required for future hair growth. The degree of visible inflammation varies, and some patients may have relatively few symptoms even while the disease remains active.

As affected follicles are progressively destroyed, they are replaced by scar tissue and normal follicular openings disappear. Once this process is complete, inflammation may become much less obvious and the scalp can appear smooth or shiny. At that stage, meaningful regrowth is generally not expected because the follicle itself has been permanently lost.

Primary and Secondary Scarring Alopecia

Scarring alopecia can broadly be divided into primary and secondary forms.

In primary cicatricial alopecia, the hair follicle itself is the principal target of the inflammatory disease. Damage to critical structures within the follicle can eventually lead to permanent destruction and replacement by fibrous scar tissue.

Primary scarring alopecias have traditionally been classified according to the predominant type of inflammatory cells seen around affected follicles on biopsy, most commonly lymphocytic, neutrophilic or mixed. This classification remains useful, although individual diseases can show overlapping features and biopsy findings may vary according to the stage and activity of the condition.

In secondary scarring alopecia, the follicle is destroyed as a consequence of another injury or disease affecting the skin rather than being the primary target. Burns, radiation, severe infection, physical trauma, tumors and certain inflammatory or infiltrative disorders can all result in permanent secondary hair loss. Advanced traction alopecia can also produce permanent follicular damage.

The distinction matters because treatment must address the underlying disease or injury responsible for the follicular destruction.

Major Types of Primary Scarring Alopecia

Primary scarring alopecia includes several distinct diseases. Although they share the potential to permanently destroy hair follicles, their patterns, symptoms and biological mechanisms can differ considerably.

Lichen Planopilaris

Lichen planopilaris, commonly abbreviated LPP, is an inflammatory scarring alopecia in which immune activity targets the upper portion of the hair follicle. It often produces irregular areas of hair loss with redness and scale concentrated around remaining hairs. Itching, burning, tenderness or pain may occur, although some patients have few symptoms.

As follicles are destroyed, normal follicular openings disappear and affected areas become permanently hairless. Active inflammation is often most apparent around the edges of an expanding area rather than in the smooth scarred center.

Treatment is directed at suppressing inflammation and preserving follicles that have not yet been destroyed.

Frontal Fibrosing Alopecia

Frontal fibrosing alopecia, commonly abbreviated FFA, is generally considered part of the lichen planopilaris spectrum. It characteristically causes progressive recession of the frontal and temporal hairline and frequently involves the eyebrows.

The receding hairline may leave behind a smooth, pale band of skin where follicles have been permanently lost. Some patients develop redness or scaling around remaining hairs, facial bumps, itching or discomfort, while others experience very few symptoms.

FFA occurs most often in women, particularly around or after menopause, but it can also affect younger women and men. The disease may continue progressing for years, making early diagnosis and treatment important.

Fibrosing Alopecia in Pattern Distribution

Fibrosing alopecia in pattern distribution, commonly abbreviated FAPD, is a scarring hair loss disorder that can resemble ordinary androgenetic alopecia because it predominantly affects areas of the scalp normally involved in male or female pattern hair loss.

Patients may show follicular miniaturization together with redness, scale or inflammation around affected follicles and evidence of progressive fibrosis. Because the distribution can initially resemble common pattern hair loss, the diagnosis may be missed unless the scalp is examined carefully with trichoscopy and, when appropriate, biopsy.

FAPD shares clinical and microscopic features with both androgenetic alopecia and lichen planopilaris, and its precise classification continues to be studied. Recognition is important because treatment must address the inflammatory scarring component rather than treating the condition as pattern hair loss alone.

Central Centrifugal Cicatricial Alopecia

Central centrifugal cicatricial alopecia, commonly abbreviated CCCA, usually begins near the center or crown of the scalp and gradually expands outward. It is diagnosed most frequently in Black women, although it can occur in men and in people of other racial backgrounds.

Early signs may include hair breakage, reduced density, itching, burning, tenderness, scaling or changes in scalp texture. Some patients experience little or no discomfort.

CCCA was once attributed largely to hair grooming practices. It is now understood to be a more complex inflammatory disorder involving biological and genetic susceptibility, while mechanical and chemical stress may contribute in some individuals.

As the disease progresses and follicles are destroyed, affected areas can become permanently hairless.

Discoid Lupus Erythematosus

Discoid lupus erythematosus, or DLE, is a form of chronic cutaneous lupus that can involve the scalp and permanently destroy hair follicles.

Affected areas may show redness, adherent scale, changes in pigmentation, follicular plugging, skin thinning and eventual scarring. Because scalp DLE can resemble other forms of scarring alopecia, clinical examination and scalp biopsy may be necessary to establish the diagnosis.

Neutrophilic Scarring Alopecias

Some primary scarring alopecias involve inflammation in which neutrophils, a type of white blood cell, play a prominent role.

Folliculitis decalvans can produce recurrent pustules, crusting, inflammation and progressively expanding areas of scarring hair loss. Several hairs may emerge together from a single apparent opening, creating a characteristic finding known as hair tufting. Bacteria, particularly Staphylococcus aureus, may contribute to the disease, but folliculitis decalvans is more complex than a simple scalp infection.

Dissecting cellulitis of the scalp is a deeper inflammatory disorder that can cause painful nodules, abscesses, drainage and interconnected channels beneath the skin. Repeated inflammation can eventually lead to extensive scarring hair loss. It belongs to a broader group of follicular occlusion disorders and can occur in people who also have hidradenitis suppurativa or severe acne.

These disorders require accurate diagnosis because their treatment differs substantially from lymphocytic conditions such as LPP, FFA and CCCA.

Signs That Should Raise Concern for Scarring Alopecia

Scarring alopecia does not always begin with an obvious bald scar. Early disease can resemble more common forms of hair loss, which is one reason diagnosis may be delayed.

Warning signs include loss of normal follicular openings, redness or scale around individual hairs, persistent burning or tenderness, significant itching, pustules, crusting, drainage, hair tufting, progressive eyebrow loss, recession of the frontal hairline, expanding loss at the crown, or areas of scalp becoming unusually smooth or shiny.

The absence of pain or obvious inflammation does not exclude scarring alopecia. Some patients have relatively quiet disease while follicles continue to be damaged.

Diagnosis and Scalp Biopsy

Diagnosing scarring alopecia requires more than determining that hair has been lost. The specific disease should be identified whenever possible because treatment varies according to the underlying inflammatory process.

Evaluation generally includes a detailed medical history, examination of the distribution of hair loss and careful inspection of the scalp and remaining follicles. Symptoms such as itching, burning, pain, tenderness, pustules or drainage and the rate of progression can provide important clues.

Trichoscopy allows magnified examination of follicular openings, scale, redness, pigmentation patterns and other changes that may help distinguish one form of scarring alopecia from another.

More than one form of hair loss can also be present at the same time. A patient with scarring alopecia may also have androgenetic alopecia, traction alopecia, telogen effluvium or another hair disorder. Identifying these overlapping conditions matters because controlling the inflammatory scarring disease does not necessarily address every cause of thinning present on the scalp.

A scalp biopsy is often necessary when primary scarring alopecia is suspected. Ideally, tissue is taken from an area where disease remains active rather than from the center of a completely smooth, longstanding scar. Once the disease has reached an advanced stage, the inflammation responsible for the original damage may no longer be visible, making it more difficult to determine which disorder caused the hair loss.

Clinical examination, trichoscopy and pathology should therefore be interpreted together.