- Primary cicatricial (scarring) alopecia results from damage or destruction of the hair follicles stem cells by:
- Inflammatory (usually noninfectious) processes.
- Infection: e.g., "kerion" tinea capitis and necrotizing herpes zoster.
- Other pathologic processes: Surgical scar, primary or metastatic neoplasm.
- Manifestations: Effacement of follicular orifices in a patchy or focal distribution, usually in scalp or beard.
- The end result is effacement of follicular orifices and replacement of the follicular structure by fibrous tissue (Table 31-3).
- Scarring is irreversible. Therapies are ineffective for scar. Treatment is geared at preventing further scarring from persistent inflammation and to control bacterial overgrowth in relevant disorders.
Chronic Cutaneous (Discoid) Lupus Erythematosus (CCLE): See Section 14.
- May occur without other manifestations or serologic evidence of lupus erythematosus.
- Manifestations:
- CCLE: erythematous plaques (Figs. 31-13, 31-14, 31-15). Keratotic follicular plugs ("carpet tacks"). Scattered. Variable in number. May become confluent. Postinflammatory hypopigmentation, and/or follicular plugging.
- SLE: Diffuse scalp erythema with diffuse hair thinning (Fig. 31-14).
- Tumid LE: Violaceous dermal inflammatory plaque with overlying hair loss.
- Dermatopathology: See "Lupus Erythermatosus" in Section 14.
LICHEN PLANOPILARIS (LPP) See "Lichen Planus" in Section 14.
- Follicular lichen planus (LP) is associated with cicatricial scalp alopecia, resulting in permanent hair loss (Fig. 31-16).
- Lichen planopilaris (LPP) may or may not be associated with lichen planus of the skin or mucosa.
- Most commonly affects middle-aged women.
- Manifestations in scalp: Perifollicular erythema ± hyperkeratosis. Violaceous discoloration of scalp. Prolonged inflammation results in scarring alopecia. In some cases, follicular inflammation and scale are absent, with only areas of scarring alopecia, so-called footprints in the snow or pseudopelade. Distribution: Most common on parietal scalp; also affects other hair-bearing sites such as the groin and axilla.
- Symptoms: Scalp pain.
- Variants:
- Graham-Little syndrome: LP-like lesions + follicular "spines"/keratosis pilaris-like lesions in areas of alopecia on scalp, eyebrows, axillary, and pubic areas.
- Frontal fibrosing alopecia: Frontotemporal hairline recession and eyebrow loss in postmenopausal women with perifollicular erythema (Fig. 31-17); histology shows LPP.
Pseudopelade of Brocq- End stage of all noninflammatory scarring alopecias and a variety of initially inflammatory disorders.
- Manifestations:
- Early lesions: Discrete, smooth, skin- or pink-colored irregularly shaped areas of alopecia without follicular hyperkeratosis or perifollicular inflammation (Fig. 31-18).
- Pattern of alopecia: Early moth-eaten pattern with eventual coalescence into larger patches of hair loss ("footprints-in-the-snow").
- Dermatopathology: Similar to lichen planopilaris.
Central Centrifugal Scarring Alopecia (CCSA)- Synonyms: Follicular degeneration syndrome, hot comb alopecia, and pseudopelade.
- Most commonly occurs in black women. Relation to chemical processing, heat, or chronic tension on the hair is uncertain, but they are best avoided.
- Slowly progressive alopecia begins in the crown/midvertex and advances centrifugally to surrounding areas.
- Dermatopathology: Earliest most distinctive change is premature desquamation of the inner root sheath with later changes through the outer root sheath, loss of the follicular epithelium, and replacement with fibrous tissue.
- Alopecia Mucinosa (Follicular Mucinosis)
- Erythematous lesions (papules, plaques, or flat patches) of alopecia, occurring mainly on the scalp and/or face.
- Dermatopathology: Prominent follicular, epithelial/sebaceous gland mucin, and perifollicular lymphohistiocytic infiltrate without concentric lamellar fibrosis.
- May be symptom of cutaneous T-cell lymphoma (see Section 21).
- Folliculitis Decalvans.
- Pustular folliculitis leading to hair loss. Surviving hairs clustered, emerging from a single follicular orifice (tufted folliculitis).
- Bogginess or induration of scalp/beard with pustules, erosions, crusts (Fig. 31-19), and scale.
- Staphylococcus aureus infection is common. Whether S. aureus infection is the primary process or secondary is uncertain.
- Dermatopathology: Acute suppurative folliculitis, early.
- Scarring alopecia is irreversible. Systemic antibiotics, rifampin, systemic and/or topical and/or intralesional glucocorticoids, and systemic retinoid have been used. S. aureus infection should be documented and treated with appropriate antimicrobial agent.
Dissecting Folliculitis- Synonyms: Dissecting cellulitis, perifolliculitis abscedens et suffodiens.
- Race: Most common in black men.
- Initial deep inflammatory nodules, primarily over the occiput, that progress to coales cing regions of boggy scalp (Fig. 31-20). Sinus tracts may form; purulent exudates can be expressed. S. aureus secondary infection is common.
- Dermatopathology: Early follicular plugging and suppurative follicular/perifollicular abscesses with mixed inflammatory infiltrate; later, foreign-body giant cells, granulation tissue, scarring with sinus tracts.
- Scarring alopecia is irreversible. S. aureus infection should be documented and treated with appropriate antimicrobial agent.
- Follicultis Keloidalis Nuchae.
- Synonym: Acne keloidalis (nuchae).
- Occurs most commonly in black men.
- Usually occurs on the occipital scalp and nape of the neck, starting with a chronic papular or pustular eruption (Fig. 31-21). Keloidal scar formation may occur.
- Early mild involvement may respond to intralesional triamcinolone. If S. aureus is isolated on culture, treat with appropriate antimicrobial agent.
Pseudofolliculitis Barbae- Synonym: "razor bumps."
- Occurs commonly in black men who shave.
- Related to curved hair follicles. Cut hair retracts beneath skin surface, grows, and penetrates follicular wall (transfollicular type) or surrounding skin (extrafollicular type), causing a foreign-body reaction.
- Distribution: Any shaved area, that is, beard (Fig. 31-22), scalp, or pubic.
- Keloidal scarring in varying degrees occurs at involved sites.
- S. aureus secondary infection is common.
Acne Necrotica- Pruritic or painful erythematous follicular-based papule with central necrosis, crusting, and healing with depressed scar.
- Lesions occur on anterior scalp, forehead, and nose; at times, the trunk.
- Dermatopathology: Lymphocytic necrotizing folliculitis.
- Poor response to treatment. Systemic antimicrobial agents and isotretinoin reported to be effective.
Erosive Pustular Dermatosis of Scalp- A disease of the elderly, mainly women, although pediatric cases do occur.
- Manifestations: Chronic, boggy, crusted plaque(s) on the scalp overlying exudative erosions and pustules, eventually leading to scarring alopecia.
- May follow trauma or treatment of actinic keratoses.
- Dermatopathology: Lymphoplasmacytic infiltrate with or without foreign-body giant cells and pilosebaceous atrophy.
- Poor response to therapy. Treat documented S. aureus infection.
Laboratory Examination
SCALP BIOPSY 4-mm punch biopsy including subcutaneous tissue, prepared for horizontal section. A second 4-mm punch biopsy specimen for vertical sections and direct immunofluorescence, particularly if lupus is suspected.
GLUCOCORTICOIDS Topical high-potency and intralesional glucocorticoids (e.g., triamcinolone) are the mainstay of treatment, improving symptoms and hair growth.
CALCINEURIN INHIBITORSTacrolimus and pimecrolimus can be helpful as topical steroid-sparing agents.
SYSTEMIC IMMUNOSUPPRESANTSMethotrexate, cyclosporine, mycophenolate, azathioprine, and others have been used in those with associated systemic conditions such as systemic lupus.
ANTIBIOTICS May be effective, especially if S. aureus infection is documented. Anti-inflammatory properties of hydroxychloroquine and doxycycline have also been used, even in the absence of documented infection, particularly for lymphocytic scarring alopecias in early clinical presentation (LPP and, CCSA).
5α-REDCUTASE INHIBITORSFinasteride and dutasteride are amongst the most efficacious treatments for frontal fibrosing alopecia.
PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR (PPAR)-γ LIGANDS Pioglitazone has been proposed as a treatment but evidence is lacking in stabilizing hair growth of lymphocytic alopecia.
RETINOIDS Case reports document efficacy in lymphocytic alopecia (FFA) with isotretinoin at lower doses (20 mg).