Lichen planus and lichenoid dermatosis Flashcards
Difference between bullous LP vs LP Pemphigoides?
In bullous LP the bullae occur over existing longstanding LP lesions
What are the two types of LP that do have eos?
Drug-induced and hypertrophic (which makes sense since they are really itchy)
What lesions can longstanding hypertrophic LP lead to?
Multiple KAs or follicular-based SCC
What is the antibody target in LP pemphigoides?
BPAG-2 bullous pemphigoid antigen 180
What skin types is LP pigmentosus m/c in?
Types III and IV
What underlying disease is most associated with oral erosive lichen planus?
HCV
What LP have risk of developing SCC
hypertrophic, erosive, vulvovaginal, and desquamative
What are the papular things that follow lines of blaschko?
- Linear porokeratosis
- Linear Darier
- Linear lichen planus (LP)
- Lichen striatus
- ILVEN
- Blaschkitis
- Linear graft-versus-host disease (GVHD)
- Linear psoriasis
What is more common, cutaneous or oral lichen planus?
Oral!
Cutaneous LP = 1% of adults, oral LP = 4% of adults
What is the most common age for LP?
Middle aged adults (40-50 y/o), F>M
What forms of LP are associated with HCV?
Oral ulcerative and erosive LP
In North America the association between HCV and other forms was not seen, but this was found in other areas (Asia, South America, Europe, Middle East)
What forms of LP is hepatitis B vaccine-associated with?
In children associated with oral LP and bullous LP (otherwise uncommon presentation)
What should always be thought of with oral LP?
Contact allergens such as mercury amalgam, copper, and gold
What contact allergies are associated with oral LP?
Mercury amalgam, copper, and gold
Will the oral LP get better if the contact allergen is removed?
Yes, 95% will improve w/ removal, even w/ negative patch test 75% clear when the metal is removed
What are the most common drugs associated with LP/lichenoid drug reaction?
HCTZ, beta-blockers, ACE (captopril), antimalarials, gold salts, TNF-alpha, NSAIDS, penicillamine and quinidine
What are the most common sites of involvement of LP?
Oral mucosa (#1), ventral wrists/forearms, dorsal hands, shins, genitalia, presacral area and neck
In what percentage of cases is the oral mucosa involved?
75% (often the only site, only 10% of those w/ oral LP will get LP elsewhere)
Will those with oral LP only get cutaneous LP?
10% chance
What is the prototypical clinical presentation of LP?
Pruritic, purple-violaceous, polygonal, flat-topped papules
- can be umbilicated
- Wickham’s striae often present (small grey-white puncta)
- Koebnerization very common
What are the classic features of LP on histology?
orthohyperkeratosis, wedge-shaped hypergranulosis under areas of orthohyperkeratosis, irregular acanthosis w/ “saw-toothed” rete ridges (from destroyed rete), vacuolar degeneration of the basal layer, apoptotic keratinocytes confined to the basal layer of epidermis with some falling into the superficial dermis (cytoid/civatte/colloid bodies), and superficial dermal band-like (“lichenoid”) lymphocytic infiltrate
What is the difference between vacuolar and lichenoid interface dermatitis?
The density of the infiltrate –> lichenoid infiltrates are denser so you will see more dyskeratotic cells etc (Nousari pearl)
LP usually lacks eos, what subtypes can have eos?
Drug-induced LP, hypertrophic LP
LP generally lacks parakeratosis, what are the exceptions?
Drug-induced LP and Oral LP
If you saw dyskeratotic cells through the epidermis but with a lichenoid-like interface what might you think about?
Graft versus host, paraneoplastic pemphigus, can be fixed-drug, EM, SJS/TEN (but acute horn in those)
What DIF findings are seen in LP?
“shaggy” fibrinogen along BMZ; colloid bodies stain with IgM (>IgA, IgG, C3)
What is the prognosis of LP?
Most forms resolved in 1-2 years (60% by year 1)
Which types of LP can be more persistent?
Oral (especially ulcerative), hypertrophic, and nail LP
What other mucosal surfaces need to be evaluated in erosive oral LP ?
Eyes (conjunctival erosions) and esophagus
Which forms of LP have an increased risk for SCC?
Hypertrophic LP, oral (ulcerative type), and vulvovaginal LP
What is the clinical presentation of keratosis lichenoides chronica?
Symmetric eruption on extremities and trunk
- Violaceous keratotic papules coalescing into plaques w/ linear to reticular arrangement
- Nails and scalp can be involved
classically has greasy sebopsoriasis-like centrofacial plaques
Treatment for keratosis lichenoid chronica?
Chronic and progressive
No effective treatments, PUVA maybe, other treatments like CS (topical and intralesional), methotrexate, etc have been unsuccessful
Histologic differences from LP and keratosis lichenoides chronica/
Largely mirror those of LP –> thought by some to be a variant and not a separate disease
What are the clinical features of erythema dyschromicum perstans?
Asymptomatic, symmetric eruption of upper trunk, neck, and proximal extremities
Characterized by slow onset of slate grey-brown or grey-blue, oval macules and patches w/ erythematous rim
What population is most affected by erythema dyschromicum perstans?
Latin Americans
What is the histology of erythema dyschromicum perstans?
Subtle basal vacuolar change (usually only discernable at the active inflammatory edge), numerous dermal melanophages, +/− band-like dermal lymphocytic infiltrate (sparse)
What is the DIF of erythema dyschromicum perstans?
Identical to LP
What is the prognosis of erythema dyschromicum perstans?
70% of kids resolve in 2-3 years, adults who get it tend to be more persistant
Treatment for erythema dyschromicum perstans?
Clofazamine (ToC), dapsone, and LP tx
What is the treatment for LP?
First line: Topical and intralesional corticosteroids. Intralesional forms good for hypertrophic LP, more severe forms might need systemic
TCIs: good for oral LP, (some concern for the theoretical increase in risk for oral LP of SCC)
MTX: useful for generalized LP (>90% response rate)
Acitretin: effective in recalcitrant LP (64% have
significant improvement)
Metronidazole: generalized LP (79% effective)
Hydroxychloroquine: mainly used for LPP/frontal fibrosing alopecia
Oral cyclosporine (recalcitrant cases)
Phototherapy (UVB, UVA1, and PUVA)
What treatment is used for lichen planopilaris or front fibrosing alopecia?
Can use topical steroids but hydroxychloroquine can be used in these cases
Where do lichenoid keratoses usually arise from?
Irritated AK or SK
Clinical appearance of lichenoid keratosis?
Solitary, pink or red-brown, scaly, 0.5–1.5 cm plaques; lesions often confused for BCC
Where are the most common locations for lichenoid keratosis?
Forearm, upper chest> shins in women and other sun-damaged areas
What is the histology of a lichenoid keratosis?
similar to LP, but often has eosinophils, spongiosis, parakeratosis, and less wedge-shaped hypergranulosis than LP
What caution should be considered with lichenoid keratosis?
Elston showed that 1-2% of these may actually demonstrate regressing melanoma in situ on deeper sections
In what age ranges is lichen nitidus seen?
Children and young adults
What is the morphology of lichen nitidus?
Multiple/grouped pinpoint, uniform, discrete, shiny, flat-topped or umbilicated, flesh-colored papules
What can lichen nitrides look like in darker skinned patients?
hypopigmented
Is koebnerization common in lichen nitidus?
Yes!
What are the most common sites of lichen nitidus?
Genitalia, lower abdomen, dorsal hands, flexor wrists, and inner thighs
What areas are usually spared by lichen nitidus?
Oral, nail, and palm/sole involvement uncommon
Classic histology of lichen nitidus?
“Ball in claw” description
Well circumscribed, superficial dermal inflammatory nodule comprised of lymphocytes, histiocytes, and giant cells confined between two to three rete ridges; inflammatory infiltrate is surrounded by hyperplastic epidermal rete ridges that “clasp the dermal infiltrate”
- Infiltrate is more “mixed” than LP (giant cells and CD1a+ Langerhans cells)
- Interface changes can be vacuolar or lichenoid
- Atrophic overlying epidermis w/ loss of granular layer +/− parakeratotic cap
What is the prognosis of lichen nitidus?
60-70% of cases resolve spontaneously within 1 yr
Treatments for lichen nitidus?
More for symptoms, topical steroids, TCI’s and phototherapy
What is an important ddx for lichen nitidus in young black adults?
Disseminated and recurrent infundibofolliculitis: pruritic follicular-based eruption of trunk and proximal extremities often hx of atopic dermatitis
- Worsened by hot and humid environments
- Rx = UVR or oral retinoids
DDx for lichen nitidus?
Lichen spinulosis: follicular hyperkeratotic papules w/ central keratotic spine on neck, buttocks, abdomen, and upper arms
What is the average age of lichen striatus?
4 y/o
What comorbidity is often seen w/ lichen striatus?
50% of affected children have atopic dermatitis
What time of year does lichen striatus more commonly occur in
Spring and summer
What is the clinical description of lichen striatus?
Asymptomatic 2–4 mm pink or hypopigmented scaly papules, linear/Blaschkoid distribution on the Extremities ≫ face, trunk, buttocks
-Nail dystrophy may occur if a digit is affected
Most common distribution of lichen striatus?
Extremities ≫ face, trunk, buttocks
Treatment and prognosis of lichen striatus?
Topical steroids and TCIs
-Resolves spontaneously in 3–24 months
What are the other names of lichen sclerosis?
Lichen sclerosis, lichen sclerosis et atrophicus, and balanitis xerotica obliterans
Epidemiology of lichen sclerosis?
F ≫ M
- whites > non-whites
- Any age, but has bimodal peaks: Major peak = 40–50 y/o post-menopausal females
Second peak = prepubertal girls (8–13 yo)
What comorbidities are often associated with lichen sclerosus?
Autoimmune dz (especially in women)
- Most common association is with autoimmune thyroid disease (15%)
- Also: pernicious anemia, localized scleroderma/morphea, psoriasis, and vitiligo
Most common distribution for lichen sclerosus?
Most commonly occurs on the anogenital region (85% of cases)
- Other locations only account for 15%
What is lichen sclerosus called when located on the penis?
balanitis xerotica obliterans
What can balanitis xerotica obliterans lead to?
Phimosis
Are antibodies seen in lichen sclerosus and if so which ones?
Yes, ECM-1 IgG antibodies are seen in 80% of cases
What is ECM-1?
Glycoprotein involved in regulation of BMZ integrity, collagen fibril assembly and other functions
What effect can hormones have on lichen sclerosus?
Predominance in postmenopausal women, resolution in pregnancy, and increased OCP use in pts
What is the clinical appearance of classical lesions of lichen sclerosus?
Classic lesions: sclerotic, ivory-white, atrophic, and flat-topped papules coalescing into plaques
- Follicular plugging more prominent in extragenital
LS&A
Classic genital dz is usually symptomatic w/ burning, itching, pain. Extra-genital lesions are generally asymptomatic
Can lichen sclerosus affect the vagina and mouth?
Only very rarely, different from LP in that regard
What areas are often involved in anogenital lichen sclerosus in women?
Most commonly affects vulvar and perianal area with classic “figure of 8” pattern in women (rarely see perianal involvement in men)
What symptoms can be seen with anogenital lichen sclerosus?
Pruritus, soreness are most typical (often severe) these can lead to dysuria, constipation (especially in kids; related to pain with defecation), dyspareunia, and discharge
How does anogenital lichen sclerosus progress in women?
Starts as well-demarcated, thin erythematous plaques that may have focal superficial erosions –> epidermal atrophy, dermal scarring, hypopigmentation, dermal hemorrhage/bruising, and fissures –> fusion of labia minora to majora, obliteration of clitoral hood, and narrowing of vaginal introitus
What if you see purpuric or ecchymotic lesions in lichen sclerosis?
These are often part of the disease and can lead to misdiagnosis as sexual abuse
Is there an increased risk of SCC in lichen sclerosus?
Yes, 5% risk of SCC for anogenital lichen sclerosus
What are the most common areas of extra-genital lichen sclerosus?
Upper trunk/neck, proximal upper extremities, and flexor wrists
What is the disease progression of extragenital lichen sclerosus?
Disease evolution: begins as polygonal blue-white
shiny papules –> coalesce into sclerotic plaques with ivory white color –> follicular plugging, telangiectasias, and bruising
What is the histology of lichen sclerosus?
Mnemonic: “Red, white, and blue sign” orthohyperkeratotic stratum corneum (pink-red), hyalinized/edematous papillary dermis (pale/white), and band-like lymphocytic infiltrate (blue band)
Compact orthohyperkeratosis, follicular plugging, epidermal atrophy with mild vacuolar interface changes, and papillary dermal edema or homogenization w/ underlying lichenoid lymphocytic infiltrate
What are the treamtent for lichen sclerosus?
- First lineultra-potent topical steroids (clobetasol): in adults and children, it is considered safe even if used long-term.
- Circumcision: (ToC) in males with phimosis
- Second line: Topical calcineurin inhibitors (TCIs)
- Refractory cases: PUVA (Psoralen and UVA), UVA1, systemic immunosuppressants
In what disease is ECM-1 mutated in?
Lipoid proteinosis
Prognosis of lichen sclerosus?
May resolve spontaneously in childhood (especially in puberty for girls), but relapsing course in adults.
Risk of SCC in lichen sclerosus?
Up to 50% of all vulvar SCCs occur in setting of LS&A
Estimated 5% risk of genital LS&A progressing to SCC
- Vulvar SCC in setting of LS&A has recently been shown to be distinct from HPV-induced vulvar SCC
○ Much higher risk of developing invasive disease
(33% vs 5.7%)
○ SCC due to LS&A may be difficult to diagnose
histologically because it is well-differentiated –>
mistaken for reactive epidermal hyperplasia
- Up to 55% of penile SCC is a/w LS&A
