Lichen Planopilaris

What is it?

Lichen planopilaris (LPP) is a chronic inflammatory condition that causes permanent, scarring hair loss (cicatricial alopecia). It is the follicular form of lichen planus — a condition in which the immune system attacks the hair follicles, destroying them and replacing them with scar tissue. Once a follicle is destroyed, the hair in that area cannot regrow.

Who is affected?

LPP predominantly affects middle-aged women, though it can occur in men and at any age.

• Prevalence: LPP is uncommon but accounts for approximately 43% of all primary scarring alopecia cases
• Age: Most commonly diagnosed between ages 40 and 60
• Gender: Women are affected approximately 5 times more often than men
• Ethnicity: Occurs in all ethnic groups; no clear ethnic predisposition

What causes it?

LPP is an autoimmune condition in which cytotoxic T-lymphocytes (a type of immune cell) attack the stem cells of the hair follicle, located in a region called the bulge.

• Immune privilege collapse: The hair follicle normally shields its stem cells from immune attack; in LPP, this protection breaks down, allowing immune cells to infiltrate and destroy the follicle
• Inflammatory cascade: Interferon-gamma drives inflammation around the follicle, leading to fibrosis (scarring) and permanent follicle loss
• Potential triggers: Certain medications (checkpoint inhibitors, beta-blockers), viral infections (hepatitis C), and hormonal changes have been implicated, though in most cases no specific trigger is identified
• Genetic predisposition: A familial tendency has been observed, but specific genetic markers have not been definitively identified

What are the clinical features?

LPP typically presents with patches of hair loss on the scalp that progressively expand.

• Perifollicular erythema: Redness surrounding individual hair follicles at the edges of bald patches
• Follicular hyperkeratosis: Small, rough scales forming plugs around hair shafts (peripilar casts)
• Scalp symptoms: Itching, burning, pain, or tenderness of the affected areas (trichodynia)
• Scarring: Smooth, shiny, pale areas where hair follicles have been permanently destroyed — follicular openings are absent
• Pull test: Hair at the margins of active patches is easily pulled out

Three clinical subtypes are recognized:

• Classic LPP: Scattered patches of scarring hair loss, mainly on the vertex and parietal scalp
• Frontal fibrosing alopecia (FFA): Progressive, symmetrical recession of the frontotemporal hairline, often with eyebrow loss; most common in postmenopausal women
• Graham-Little-Piccardi-Lassueur syndrome: A rare triad of cicatricial scalp alopecia, non-scarring hair loss of the axillae and groin, and follicular keratotic papules on the trunk

How is it diagnosed?

Diagnosis relies on a combination of clinical examination, trichoscopy, and histopathology.

• Clinical examination: Patches of scarring alopecia with perifollicular erythema and follicular keratosis at the borders; positive pull test at active margins
• Trichoscopy (dermoscopy of the scalp): Reveals peripilar casts (cylindrical scales around hair shafts), perifollicular erythema, blue-grey dots, loss of follicular openings in scarred areas, and tufted follicles
• Scalp biopsy: Shows a band-like lymphocytic infiltrate at the level of the infundibulum and isthmus, interface dermatitis of the outer root sheath, and perifollicular fibrosis (lamellar fibrosis around the follicle)
• Direct immunofluorescence: Colloid bodies (IgM) at the basement membrane zone; helps differentiate from discoid lupus erythematosus
• Lichen Planopilaris Activity Index (LPPAI): A validated scoring tool used to track disease activity based on symptoms, signs, and pull test results

What treatment options are available?

There is no cure for LPP. Treatment aims to halt disease progression, reduce symptoms, and preserve remaining hair follicles. Hair that has already been permanently lost cannot be restored.

For mild or localized disease:

• High-potency topical corticosteroids (clobetasol propionate 0.05%) applied to active areas
• Intralesional corticosteroid injections (triamcinolone acetonide 5–10 mg/mL) every 4–6 weeks
• Topical calcineurin inhibitors (tacrolimus 0.1%) as a steroid-sparing alternative

For moderate to severe or progressive disease:

• Hydroxychloroquine 200 mg twice daily — the most commonly used systemic agent for LPP
• Methotrexate 15 mg/week — considered when hydroxychloroquine is insufficient
• Doxycycline 100 mg twice daily — for its anti-inflammatory properties
• Pioglitazone 15–30 mg daily — targets a specific molecular defect (PPAR-gamma deficiency) observed in LPP

Adjunctive measures:

• Topical minoxidil to support remaining follicles
• Avoidance of physical or chemical hair damage (tight hairstyles, excessive heat, chemical treatments)
• Psychological support — hair loss can significantly affect self-esteem and quality of life

Prognosis: LPP follows a chronic, relapsing course. Early treatment is essential, as hair loss in scarred areas is permanent. With appropriate therapy, disease progression can often be slowed or halted, but sustained treatment is typically required — discontinuation is associated with a relapse rate of approximately 30%.

Key points for patients

• LPP causes permanent hair loss in affected areas — early treatment helps preserve remaining hair
• The condition is not contagious and is not caused by anything you did
• Treatment can control the disease but does not cure it; long-term therapy is often necessary
• When to seek medical attention: Progressive hair loss with scalp itching, burning, or tenderness; visible scarring or smooth hairless patches; eyebrow thinning or loss of body hair
• Regular dermatological follow-up is important to monitor disease activity and adjust treatment
• Up to 50% of patients with LPP may also develop lichen planus affecting the skin, mouth, or nails