Scarring Alopecia (Cicatricial Alopecia)

Scarring alopecia, also known as cicatricial alopecia, refers to a group of hair loss disorders that may affect up to 3% of individuals experiencing hair loss. It occurs worldwide, impacting otherwise healthy men and women of all ages.

While each specific diagnosis within this category is relatively uncommon, notable examples include dissecting cellulitis, eosinophilic pustular folliculitis, follicular degeneration syndrome (formerly referred to as “hot comb” alopecia), folliculitis decalvans, lichen planopilaris, and pseudopelade of Brocq. Scarring alopecia can also be part of more comprehensive conditions like chronic lupus erythematosus, where various organs of the body may be involved.

Despite the diversity of scarring alopecia forms, the common underlying theme is the potential for permanent and irreversible destruction of hair follicles, leading to their replacement with scar tissue.

Most cases of scarring alopecia initially manifest as small patches of hair loss that may gradually expand over time. While some instances of hair loss occur gradually and go unnoticed due to minimal symptoms, others are accompanied by intense itching, burning, and pain, progressing rapidly.

The appearance of scarring alopecia patches often differs from that of alopecia areata, with the edges of the bald patches appearing more irregular. The damage to the hair follicles occurs beneath the skin surface, often resulting in minimal visible changes on the scalp skin other than patchy hair loss. Affected areas may exhibit smoothness and cleanliness, or they could display signs of redness, scaling, pigmentation changes, or even raised blisters oozing fluids or pus.

While these visual cues can aid in diagnosis, identifying scarring alopecia based solely on hair loss patterns and scalp skin characteristics can be challenging. A definitive diagnosis often requires one or more skin biopsies to confirm the condition and specify the precise type of scarring alopecia. Typically, a small biopsy ranging from 2 to 4 mm in diameter is conducted and analyzed under a microscope. Dermatologists and pathologists examine the biopsy for indicators such as follicle destruction, deep scar tissue, and the presence and location of inflammation relative to hair follicles.

In the early stages of scarring alopecia, inflammatory cells are often present around hair follicles, believed by many researchers to contribute to hair follicle destruction and scar tissue formation. However, differing opinions exist among dermatologists, as some biopsies from individuals with scarring alopecia show minimal inflammation.

As scarring alopecia progresses, the bald patches usually cease to expand, and symptoms like inflammation, itching, burning, or pain subside. In the later stage, a skin biopsy typically reveals no inflammation around hair follicles. Bald areas often lack functional hair follicles, although in some cases, follicles at the periphery of a bald patch might survive, resulting in limited regrowth characterized by longitudinal scars beneath the skin.

Treatment Options

Given the potential for significant damage and permanent hair loss, aggressive treatment of scarring alopecia is crucial. The specific nature of treatment varies based on the diagnosis. Scarring alopecias primarily involving lymphocyte inflammation of hair follicles, such as lichen planopilaris and pseudopelade, are generally addressed with corticosteroids through topical creams and injections into the affected skin. Additionally, antimalarial and isotretinoin drugs may be prescribed.

For scarring alopecias featuring inflammation primarily by neutrophils or a mix of cells, the standard approach includes antibiotics and isotretinoin. More experimental treatments involve drugs like methotrexate, tacrolimus, cyclosporin, and even thalidomide, which have shown efficacy in treating certain forms of scarring alopecia.

Once scarring alopecia reaches the burnt-out stage, and if there has been no hair loss for a few years, surgical removal of smaller bald areas may be considered. Alternatively, bald patches can be transplanted using hair follicles harvested from unaffected regions, offering a potential solution for restoring hair in select cases.