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