What is scarring hair loss?
Scarring hair loss, or cicatricial alopecia, occurs when hair is lost and the follicle shrivels and is destroyed. Once a follicle has scarred, it cannot produce another hair, so the loss is irreversible. All forms are relatively uncommon.
Primary and secondary forms
In primary cicatricial alopecia, the disease process starts specifically within the hair follicle. In secondary cicatricial alopecia, a process in the surrounding skin damages an otherwise unaffected follicle. Deep burns, radiotherapy, skin cancer and chronic skin infections are examples of secondary causes.
Types of primary disease
Doctors classify primary forms by their visible pattern and by the inflammatory cells seen when tissue is examined under a microscope. Lymphocytic forms include classic lichen planopilaris, frontal fibrosing alopecia, Graham Little syndrome, cutaneous lupus erythematosus, pseudopelade of Brocq, central centrifugal cicatricial alopecia, alopecia mucinosa and keratosis follicularis spinulosa decalvans. Neutrophilic forms include folliculitis decalvans and dissecting cellulitis. Acne keloidalis and erosive pustular dermatosis have a mixed pattern, while some cases remain non-specific.
Treatment
Hair cannot regrow after scarring has occurred, which makes early control of inflammation important. Topical anti-inflammatory treatment, such as a corticosteroid, may be used. Ointments or lotions are often insufficient, however, and systemic treatment such as an antimalarial medicine may be considered. The best option depends on the precise type, activity and extent of the disease and requires specialist assessment.
When to see a doctor
Arrange prompt medical review for expanding areas of hair loss, particularly when the scalp looks smooth or scarred or has redness, scaling, pustules, pain or itch. A dermatologist may need to examine the scalp and take a biopsy to identify the type. Early treatment offers the best chance of protecting follicles that have not yet been permanently destroyed.