Management of Secondary Scarring Alopecia
The primary goal in managing secondary scarring alopecia is to identify and aggressively treat the underlying causative condition before irreversible follicular destruction occurs, as permanent hair loss results from replacement of pilosebaceous structures by scar tissue. 1
Understanding Secondary vs. Primary Scarring Alopecia
Secondary scarring alopecia differs fundamentally from primary forms because the hair follicle is not the primary target—rather, follicular destruction occurs as collateral damage from other scalp pathology 1, 2. The distinction matters because:
- Secondary scarring alopecia results from nonfollicular scalp conditions affecting the dermis that secondarily destroy follicles 1, 2
- Primary scarring alopecia directly targets the hair follicle as the main site of inflammation 3, 4
Diagnostic Algorithm
Initial Clinical Assessment
Determine whether scarring is present through scalp examination, as this fundamentally directs all subsequent decisions 5. Look specifically for:
- Loss of follicular ostia on dermoscopy, which distinguishes cicatricial from non-scarring alopecia 6
- Absence of yellow dots, exclamation mark hairs, and cadaverized hairs, as their presence suggests non-scarring alopecia areata rather than cicatricial alopecia 6
- Scalp inflammation or scaling, which raises concern for scarring processes 5
Identify the Underlying Cause
Secondary scarring alopecia has multiple potential etiologies 1:
- Congenital defects (e.g., congenital absence of skin) 7
- Trauma (burns, mechanical injury) 7
- Inflammatory conditions (morphea, sarcoidosis) 7
- Infections (lupus vulgaris, other deep infections) 7
- Neoplasms (rarely) 1
- Drugs (rarely) 1
Perform Skin Biopsy When Diagnosis is Uncertain
Biopsy is essential when the underlying disorder is not clinically obvious, particularly in end-stage lesions where detection of the causative condition may be difficult 8, 1. Histopathology aids in:
- Confirming scarring vs. non-scarring alopecia 6
- Identifying the specific underlying pathology 7
- Guiding treatment decisions 3
Treatment Framework
For Active Disease
Treatment must be specific to the underlying causative condition 1. The key principle is early and aggressive intervention:
- Identify the active underlying disorder through clinical examination, dermoscopy, and biopsy 1, 3
- Treat the causative condition aggressively to prevent further follicular destruction 3
- Act early, as management depends on accurate diagnosis before irreversible scarring occurs 3
For End-Stage/Inactive Scarring
Once scarring is established and the underlying condition is no longer active 1:
- Surgery is an option for localized scars 1
- Hair transplantation can be considered for localized areas of permanent alopecia 1
Critical Pitfalls to Avoid
- Do not delay biopsy when the diagnosis is uncertain, as early detection of the underlying disorder is crucial before end-stage scarring makes identification difficult 8, 1
- Do not confuse secondary scarring alopecia with primary forms, as treatment targets differ fundamentally—secondary forms require treatment of the underlying dermal/systemic condition rather than the follicle itself 1, 2
- Do not assume all scarring alopecia is primary, as various nonfollicular conditions can cause permanent hair loss 1