Lichen Sclerosus

Lichen sclerosus (LS) is a chronic, relapsing, T-cell-mediated inflammatory dermatosis that produces progressive dermal sclerosis - true scarring, not simple atrophy - of the skin it affects. It overwhelmingly favours anogenital sites: the vulva, perineum, and perianal skin in women and girls; the glans penis and prepuce in men and boys (the older term "balanitis xerotica obliterans," BXO, refers to the same disease in this location). Roughly 15-20% of patients also have extragenital disease elsewhere on the body, which behaves very differently - it is not mucosal, does not scar in the same functionally significant way, and does not carry the malignancy risk that makes genital LS a genuine long-term safety concern.^[1]

A 2024 nationwide Swedish register study - the largest and most current population-level data available - found an overall LS incidence of 80.9 per 100 000 person-years, roughly 2.4-fold higher in women (114.4) than men (47.2); the highest age-specific incidence in both sexes occurred in the 70-79-year age band (224.8 per 100 000 in women, 62.4 per 100 000 in men), while women aged 20-39 years still accounted for about 17.4% of all female cases.^[2] This administrative data understates the classically taught prepubertal peak, since LS in young girls is frequently misdiagnosed (as eczema, candidiasis, or, troublingly, mistaken for or mistaken as ruling out sexual abuse) rather than coded correctly - do not let register-level statistics lower your suspicion for LS in a prepubertal girl with anogenital itch, bleeding, or dysuria.

The same Swedish cohort found significantly elevated odds of vulvar cancer (odds ratio 8.3) and penile cancer (odds ratio 8.9) among people with LS, alongside meaningful associations with other autoimmune and sclerosing skin disease - lichen planus (odds ratio 5.6), morphea (odds ratio 6.2), and vitiligo (odds ratio 3.9) chief among them.^[2] A Canadian systematic review from the University of Toronto and Women's College Hospital similarly found an increased risk of vulvar squamous cell carcinoma (VSCC) in women with LS, though with wide heterogeneity across studies - reported absolute risk of developing VSCC ranged from 0% to 21.88%, and incidence from 1.16 to 13.67 cases per 1000 person-years.^[3] This malignancy risk, together with the entirely avoidable, irreversible architectural damage that untreated or undertreated LS causes, is why this chapter treats adequate long-term treatment - not simply symptom relief during flares - as the standard of care.

Lichen sclerosus of the vulva, extending to the perineum, in an 82-year-old woman - the classic ivory-white, "porcelain" discoloration described below. (Mikael Häggström, Wikimedia Commons, CC0)

Symptoms

Anogenital pruritus is the dominant symptom and is frequently severe and worse at night, but soreness, burning, painful fissuring, dyspareunia, and dysuria (from urine contacting fissured or atrophic skin) are all common. Painful defecation from perianal fissuring can drive stool-withholding and secondary constipation, particularly in children.^[1] A meaningful minority of patients - genital and extragenital alike - are entirely asymptomatic, with disease found incidentally on examination.

The classic anogenital appearance

Established LS produces porcelain-white to ivory, atrophic-appearing plaques with a crinkled, "cigarette-paper" texture, often with overlying hyperkeratosis. Purpura and ecchymosis - spontaneous or minimally provoked subepidermal bleeding into the sclerotic dermis - is a genuinely characteristic finding, not an alarming outlier, though it is exactly this finding that most often triggers (appropriate) concern for abuse in a child (see Special Populations). Fissuring, erosions, and areas of hyperkeratosis are common, especially in more active or longstanding disease.

In women and girls, disease classically involves the labia minora, clitoral hood/prepuce, and the skin around the introitus, extending posteriorly across the perineum to the perianal skin in a symmetric "figure-of-8" or hourglass distribution - a highly characteristic pattern once looked for deliberately. The vaginal mucosa itself is not involved - this is an important, genuinely useful distinguishing feature: mucosal (vaginal, oral) involvement should prompt reconsideration of lichen planus rather than LS (see Assessment and Diagnosis).^[1]

Progressive architectural change - why early, adequate treatment matters

Untreated or undertreated LS does not simply persist - it scars, and the resulting anatomic change is largely irreversible once established. In women this includes progressive resorption of the labia minora, adhesions burying the clitoris under fused, scarred prepuce (clitoral phimosis, sometimes with painful, retained smegma - "pseudocyst" - beneath it), and narrowing of the vaginal introitus that can make intercourse or even pelvic examination difficult or impossible. This architectural change, not simply the visible rash, is a central reason adequate treatment is started promptly and continued proactively rather than only during symptomatic flares (see Choose Initial Treatment).^[1]

Male genital lichen sclerosus (balanitis xerotica obliterans) - whitish, sclerotic induration of the glans, the presentation described below. (Sommerwind88, Wikimedia Commons, CC BY-SA 4.0)

Male genital lichen sclerosus

In men and boys, LS affects the glans and prepuce (foreskin), producing the same whitish, sclerotic induration, and is strongly associated with the uncircumcised state.^[4] The dominant, often presenting complication is progressive phimosis - an increasingly non-retractable, scarred foreskin - which can advance to the point of causing painful erections, recurrent balanitis, or obstructed urination. Meatal involvement causes progressive urethral meatal stenosis, and disease can extend into the distal urethra to cause a genuine urethral stricture, which needs specialist urologic assessment (see Special Populations).^[4]

Extragenital lichen sclerosus

Extragenital disease - most often on the trunk, breasts, proximal extremities, or wrists - produces similar porcelain-white, atrophic plaques but is usually asymptomatic, does not affect mucosa, and (unlike genital disease) is not associated with an increased malignancy risk.^[1] It can occur alone or alongside genital disease and typically needs a different treatment approach (see Choose Initial Treatment).

• Female sex - LS is meaningfully more common in women than men, though the disease is well recognized and clinically important in both.^[2]
• Age - LS has classically taught peaks in prepubertal girls and postmenopausal women, though the highest measured age-specific incidence in a large register study fell in the 70-79-year age band in both sexes; anogenital LS in a child is nonetheless a real and important diagnosis to consider, not a rarity to be talked out of.^[2]
• Uncircumcised status in males - neonatal circumcision appears protective against later development of genital LS, while circumcision performed later in childhood does not carry the same protective effect.^[4]
• Personal or family history of autoimmune disease - LS shows a well-replicated association with autoimmune thyroid disease, vitiligo, type 1 diabetes, systemic lupus erythematosus, and inflammatory bowel disease, and circulating autoantibodies against extracellular matrix protein 1 (ECM1) are detectable in the majority of patients with genital LS, making ECM1 a leading candidate autoimmune target.^[5]
• Genetic susceptibility - specific HLA class II associations (including the DRB1*12 haplotype) are overrepresented in LS, and roughly 12% of a large case series reported a family history of the disease, including reports in both monozygotic and dizygotic twin pairs.^[5]
• Koebnerization - chronic friction, mechanical trauma, and prolonged moisture exposure (urinary or fecal incontinence, occlusive clothing) can trigger or worsen LS at the site of irritation, and should be addressed as part of routine management regardless of pharmacologic treatment (see Non-Pharmacologic Treatment).^[1]

Associated conditions - reported odds ratios

The table below reflects statistically significant associations from the 2024 nationwide Swedish register study, the largest and most current population-level data source available.^[2]

These are associations, not proof of a shared causal pathway in every case - but the magnitude of the vulvar- and penile-cancer odds ratios in particular underscores why lifelong anogenital surveillance is a non-negotiable part of LS care (see Monitoring and Follow-Up), and the autoimmune-disease associations are a reasonable prompt for a basic review of symptoms (particularly thyroid) at diagnosis.

Diagnostic approach

Classic LS - porcelain-white, atrophic anogenital plaques in the figure-of-8 distribution, without atypical features - is a clinical diagnosis; a biopsy is not required to start treatment.^[1] Biopsy is recommended when:^[6]

• The presentation is atypical, or there is genuine diagnostic uncertainty.
• Malignant transformation (squamous cell carcinoma or dVIN/PeIN) is suspected - any hyperkeratotic plaque, persistent ulcer/erosion, or nodule not behaving like typical LS.
• Treatment has failed to produce the expected response after an adequate trial.
• Before starting a more potent or systemic therapy in a younger, reproductive-age woman, as an added diagnostic safeguard.^[6]
• Disease is pigmented, or extragenital disease could be mistaken for morphea.
• Every circumcision specimen removed for LS - histology is mandatory, both to confirm the diagnosis and to exclude an unsuspected precancerous or cancerous change.^[1][6]

In children, biopsy is not needed for a typical presentation and should generally be avoided given the trauma of the procedure in this population; reserve it for atypical or poorly responsive disease, using appropriate sedation or anesthesia if biopsy becomes necessary.^[1]

Histology

Take biopsies from untreated, typical-appearing (whitish) skin whenever possible, since prior treatment can blunt the characteristic findings.^[1] Classic histology shows epidermal atrophy with overlying hyperkeratosis, a band of hyalinized, sclerotic (homogenized) collagen in the papillary dermis, and a band-like lymphocytic infiltrate beneath this zone of sclerosis.

Differential diagnosis

• Control symptoms - pruritus, soreness, dyspareunia, and dysuria - which are frequently what brings a patient to care in the first place.
• Achieve and sustain remission of visible inflammatory activity (erythema, fissuring, erosions), not merely partial symptom relief.
• Prevent further, and where possible limit existing, architectural scarring - labial resorption, clitoral phimosis, introital narrowing, and penile phimosis are largely irreversible once established, making prevention the real goal rather than later correction.
• Reduce the long-term risk of malignant transformation through adequate, proactively maintained treatment - not simply treatment during symptomatic flares.
• Preserve sexual, urinary, and (in children) normal developmental function.
• Support the substantial psychological and relational burden LS can carry - visible genital change, chronic itch, and sexual dysfunction are not minor concerns and deserve direct, non-judgmental discussion.
• Maintain lifelong surveillance for malignant change, since the risk persists even in well-controlled, asymptomatic disease.

Skin care and irritant avoidance

• Stop soap, fragranced washes, wipes, and any other potential irritant or contact allergen on affected skin - use a plain, fragrance-free emollient as a soap substitute for washing instead.
• Apply a plain, fragrance-free emollient liberally and regularly as an adjunct to (not a substitute for) corticosteroid treatment, both to relieve dryness and as a protective barrier.
• Pat rather than rub the area dry, and avoid vigorous wiping after toileting.
• Choose loose-fitting, breathable (cotton) underwear and avoid prolonged occlusion or friction from tight clothing.

Managing Koebner triggers

Address urinary or fecal incontinence promptly and proactively where present, since chronic moisture exposure is a recognized trigger and aggravating factor for LS; a structured continence assessment is a genuinely useful adjunct to pharmacologic treatment in an affected patient. In children, treat constipation actively - painful defecation from perianal fissuring readily drives a stool-withholding cycle that worsens both the constipation and the local skin disease.

Sexual and pelvic-floor support

Dyspareunia and introital narrowing are common, genuinely distressing consequences of LS. Pelvic floor physiotherapy, vaginal dilator therapy, and a lubricant free of common irritants can meaningfully improve function alongside adequate disease control; refer for formal psychosexual support where dyspareunia or the visible anatomic change is affecting a patient's relationship or wellbeing.

Patient and caregiver education

• Explain clearly that LS is a chronic, lifelong condition with an excellent prognosis for symptom control, but that stopping treatment once skin looks normal is a leading, avoidable cause of relapse and progressive scarring - proactive maintenance is not optional "extra" treatment.
• Teach correct application technique explicitly, including the fingertip-unit dosing guide, to counter both under- and over-application.
• Teach the patient (or, in a child, the caregiver) to self-examine periodically, ideally with a hand mirror, and to seek prompt review for any new lump, ulcer, area of thickening, or colour change rather than waiting for the next scheduled visit (see Red Flags).
• Reassure patients that steroid phobia is a genuinely common and understandable barrier, but that appropriately dosed, appropriately monitored ultra-potent topical corticosteroid use is safe long-term and is what prevents the outcomes patients fear most - scarring and cancer.
• For families of children with vulvar LS, explain plainly why the diagnosis does not exclude a separate concern about abuse (and vice versa), and that both being considered in parallel is standard, careful practice rather than an accusation (see Special Populations).

Prepubertal girls

Vulvar LS in prepubertal girls is a genuinely important, likely under-recognized diagnosis, with mean symptom onset around age 7; presentation includes vulvar itch (the dominant symptom, reported in the large majority), soreness, dysuria, vaginal bleeding from fragile skin, and constipation from perianal fissuring.^[8] The figure-of-8 white lesion pattern remains the key clinical clue. Preferred approach examine children without requiring a gynecological examination chair or position, and avoid biopsy where the clinical picture is typical, given the trauma of the procedure in this age group; reserve it for atypical or poorly responsive disease.^[1] A potent (rather than ultra-potent) topical corticosteroid is often preferred as the starting agent given thinner pediatric skin and a theoretically greater sensitivity to steroid-related local adverse effects, stepping up to an ultra-potent agent if response is inadequate.^[1] Reported pediatric outcomes are encouraging - symptom resolution in 65-100% and complete remission in 20-70% of treated children across published series, with up to about 55% able to maintain remission without ongoing treatment - though a meaningful proportion of children need continued therapy through puberty and beyond, and long-term follow-up is recommended regardless of apparent early response, since malignancy risk, while lower than in adults, is not zero (roughly 2.2% in reported pediatric series).^[8]

The overlap with suspected sexual abuse

The purpura, ecchymosis, fissuring, and scarring of vulvar LS can closely resemble findings raised by concern for sexual abuse, and this is one of the more difficult, high-stakes overlaps in pediatric practice. Critically, LS and abuse are not mutually exclusive - the presence of one does not rule out the other, and clinicians should neither dismiss abuse concerns because "it's just LS" nor dismiss a genuine LS diagnosis because abuse has been raised.^[8] Features suggesting abuse rather than (or in addition to) LS include an older prepubertal age at presentation, a poor or atypical response to appropriate LS treatment, or coexisting findings suggestive of a sexually transmitted infection. Manage this with a calm, trauma-informed, non-accusatory approach involving clinicians experienced in pediatric anogenital assessment, and appropriate child-protection referral where indicated by the overall clinical picture - not by the presence of LS alone.^[8]

Pregnancy and childbearing-age women

LS itself does not involve the vagina and does not preclude vaginal delivery, though significant introital scarring may warrant obstetric planning (including consideration of episiotomy) to reduce the risk of severe perineal tearing.^[1] Ultra-potent topical corticosteroids can be used in pregnancy at the lowest effective dose. Avoid methotrexate and acitretin, both teratogenic - acitretin in particular requires effective contraception for at least 3 years after discontinuation. As in non-pregnant patients, confirm the diagnosis with biopsy where there is any uncertainty before starting more potent or systemic treatment, particularly in a younger, reproductive-age woman.^[6]

Men and boys

Progressive phimosis is the dominant clinical problem, and circumcision is genuinely curative for medically refractory disease confined to the foreskin - a 301-patient cohort found no progression to squamous cell carcinoma in patients managed with either adequate topical therapy or circumcision.^[4] Meatal or urethral extension needs specialist urologic input, since this disease pattern is less reliably resolved by circumcision alone and can progress to a true urethral stricture (see Choose Initial Treatment).^[4][6]

Older adults

This is the age group with both the highest measured incidence of LS and the age at which vulvovaginal atrophy from estrogen deficiency commonly coexists - do not conflate the 2, since LS needs corticosteroid-based anti-inflammatory treatment while atrophy is managed separately (often with vaginal estrogen), and treating one as though it were the other delays effective care for whichever is under-treated.^[2] Malignancy vigilance is especially important in this population, given both the higher background incidence of LS itself and of vulvar/penile cancer generally.

Renal impairment

Avoid methotrexate when eGFR is under 50 mL/min/1.73 m², per current Canadian product labelling.

Hepatic impairment

Both methotrexate and acitretin carry hepatotoxicity risk and need closer monitoring, or an alternative agent, in significant hepatic impairment.

Follow-up schedule

Review at about 3 months after starting treatment to assess response, confirm correct application technique, and address adherence barriers (including steroid phobia). For men with a good response, a further review at 6 months is reasonable; for women and girls, continue periodic review (commonly every 3-6 months initially, extending to about annually once disease is stable on maintenance therapy) for the remainder of the patient's life - LS does not "graduate" to primary-care-only, unmonitored management once controlled.^[1][6]

What every follow-up visit should include

• Direct examination of anogenital skin at every visit, not reliance on the patient's symptom report alone - early malignant change can be subtle and is not reliably symptomatic.
• A low threshold to biopsy any new hyperkeratotic area, persistent erosion or ulcer, papule, or nodule (see Red Flags), regardless of how well the rest of the disease appears controlled.^[6]
• Reassessment of adherence to proactive maintenance therapy specifically - ask directly whether the patient has continued treatment once symptoms resolved, since stopping is common and is the pattern linked to higher malignancy risk.^[7]
• Assessment for progressive architectural change (labial resorption, clitoral phimosis, introital narrowing, penile phimosis, meatal stenosis) - baseline photographs, where the patient consents, are a practical way to track this over time.
• For patients on a topical calcineurin inhibitor, methotrexate, or acitretin, the agent-specific monitoring below.

Agent-specific monitoring

• Topical corticosteroids: examine for signs of true steroid-related atrophy or contact irritation/allergy at follow-up, distinguishing this from LS's own sclerotic change - a source of real diagnostic confusion that can lead to inappropriately stopping an effective treatment.
• Topical calcineurin inhibitors: monitor tolerability (burning/stinging) and clinical response; theoretical malignancy-risk signals originate largely from the systemic transplant literature and have not been clearly borne out with topical genital use, but routine anogenital surveillance continues regardless, as it does for every LS patient.^[1]
• Methotrexate: routine CBC, liver enzymes, and renal function per usual practice; confirm eGFR before dose adjustments.
• Acitretin: baseline and periodic lipid panel and liver enzymes; reinforce the contraception requirement (at least 3 years post-treatment) at every visit for a patient of childbearing potential.

1. Confirm genuine adherence and correct application technique before labelling treatment a failure - both under-application (from steroid phobia) and simply stopping once symptoms improve are common, correctable causes of apparent treatment failure.^[7]
2. Reassess the diagnosis, and biopsy if not already done - persistent, apparently treatment-resistant disease is itself one of the standard indications for biopsy, both to confirm LS and to exclude an evolving dVIN/PeIN or squamous cell carcinoma.^[6]
3. Consider a superimposed or alternative diagnosis contributing to poor response - irritant/contact dermatitis from a product in use, candidiasis, or coexisting lichen planus are all common confounders.
4. Inadequate response to an adequate (about 3-month) course of correctly used ultra-potent topical corticosteroid: step to, or add, a topical calcineurin inhibitor (tacrolimus or pimecrolimus, off-label).^[1]
5. Severe, extensive, or genuinely refractory disease, including widespread extragenital involvement: consider systemic therapy (methotrexate first-line among systemic options, acitretin as an alternative) under specialist direction.^[1]
6. Male genital disease with phimosis unresponsive to an adequate topical steroid trial: refer for circumcision, with histologic examination of the specimen; meatal or urethral involvement needs urology referral rather than continued topical escalation alone.^[4][6]
7. Marked introital stenosis or clitoral phimosis causing significant functional impairment despite adequate medical treatment and disease control: refer for surgical assessment - proceed only once active inflammation is controlled, since operating on actively inflamed LS carries a real risk of poor healing and disease recurrence at the surgical site.
8. At any point in this pathway, a new hyperkeratotic area, non-healing ulcer/erosion, or nodule should be biopsied urgently rather than treated as simply "more resistant LS" (see Red Flags).

• Treating LS as a short course of topical steroid to be stopped once symptoms resolve, rather than transitioning to indefinite proactive maintenance - this is the single pattern most clearly linked to malignant transformation in the best available cohort data.
• Under-dosing out of steroid phobia - patients (and sometimes clinicians) applying far less than a fingertip unit, or stopping early, out of an understandable but misplaced fear of topical corticosteroid harm.
• Mistaking LS's own dermal sclerosis and pallor for steroid-induced atrophy, and inappropriately stopping an effective treatment as a result.
• Repeatedly treating anogenital itch as recurrent candidiasis or irritant dermatitis without examining for the porcelain-white, atrophic plaques of LS - a very common real-world path to delayed diagnosis.
• Dismissing vulvar LS in a prepubertal girl as too rare to consider, or conversely dismissing a genuine abuse concern because LS has been diagnosed - both possibilities can and do coexist.
• Performing a circumcision for presumed phimosis without sending the specimen for histology, missing an opportunity to confirm LS and exclude early malignant change.
• Delaying biopsy of a hyperkeratotic plaque, non-healing erosion, or nodule out of reluctance to "overreact," rather than treating this as a standard, low-threshold safety step.
• Prescribing topical estrogen, testosterone, or progesterone as treatment for LS itself, rather than reserving hormonal therapy for its own separate indication (postmenopausal vulvovaginal atrophy) where relevant.
• Assuming vaginal mucosal involvement is consistent with LS rather than reconsidering lichen planus, given the 2 conditions' distinct treatment implications and association with each other.
• Referring for surgical correction of architectural change (introital stenosis, clitoral phimosis) while disease is still actively inflamed, rather than achieving disease control first.
• Discharging a well-controlled patient from long-term follow-up altogether, rather than continuing periodic anogenital surveillance for life.

How to use this table: doses are adult doses (pediatric doses noted where they differ) and require patient-specific confirmation, including renal/hepatic adjustment. Select any drug name to open its complete Pharmasist Drug Database page.

Ultra-Potent/Potent Topical Corticosteroids (First-Line)

First-line for genital and extragenital disease alike, in an induction-then-indefinite-proactive-maintenance regimen - do not stop once symptoms resolve.

Topical Calcineurin Inhibitors (Off-Label, Second-Line)

For inadequate response to, intolerance of, or a wish to reduce cumulative exposure to topical corticosteroids. Do not cause dermal atrophy, but initial burning/stinging is common.

Systemic Agents for Severe or Refractory Disease (Off-Label, Specialist-Directed)

Reserved for severe, extensive, or genuinely refractory disease, including widespread extragenital LS not controlled by topical measures.

Lower-Potency Maintenance Option

May be substituted for the ultra-potent agent during stable maintenance in some patients, at the treating clinician's discretion; return to the ultra-potent agent for any flare.