Other Papulosquamous disorders Flashcards
Small plaque Parapsoriasis things
What is it/ lesion
description Histologically (brief)
Predominant cell type
Differential for this type of lesion
Chronic asymptomatic, erythematous scaly patches, usually <5 cm lesions in diameter
Histo: mild, nonspecific spongiotic dermatitis with parakeratosis
Cell: Predominance of CD4+ T cells with dominant T-Cell clonality in the superficial lymphoid infiltrate
Male dominance
Sometimes erythematous/ pruritic, sometimes with fine scale, generally asymptomatic `
DDx: Pityriasis rosea, Drug eruption (PR like), pityriasis lichenoides chronica, psoriasis, MF, secondary syphilis, nummular dermatitis
Large plaque parapsoriasis is / isn’t a distinct entity from small plaque
DDx of Large plaque parapsoriasis
Chance of turning into MF?
Is distinct, is thought to be even related to early MF or CTCL
Chronic, asymptomatic, erythematous larger (>5 cm) scaly patches
May or May not exhibit telangiectasia, atrophy, hypo/hyperpigmentation → this triad = poikilodermatous variant
Histo: nonspecific spongiotic dermatitis with lichenoid features, predominance of CD4+ T cells in lymphocytic infiltrate
Ddx: MF, drug eruption (MF like), psoriasis, poikilodermatous autoimmune connective tissue disease (Dermatomyositis), radiodermatitis
Rate of converting from large plaque parapsoriasis to overt lymphoma/ MF? 10-35%/ year
Standard treatments for Small and large plaque parapsoriasis
Topical corticosteroids, topical coal tar, phototherapy, ?Bexarotene, ?calcineurin inhibitors, imiquimod?
What is shown, describe
Scaly, atrophic, red-brown papules-plaques in a reticular/ net like pattern
Retiform parapsoriasis
Large plaque psoriasis with telangiectasia, atrophy, hypo/hyperpigmentation →
poikilodermatous variant
Pityriasis lichenoides spectrum (two main variants)
Pityriasis lichenoides et varioliformis Acuta (PLEVA)
Pityriasis lichenoides chronica
Both entities = recurrent crops of spontaneously regressing erythematous to purpuric papules
PLEVA lesions = occasionally vesiculopustular/ crusted
PLEVA generally CD8+ cells predominate
PLC = Scaly
PLC CD4+ cells predominate
Histo = interface dermatitis with necrotic keratinocytes with T cell infiltrate, often monoclonal
Describe the lesions
A) widespread erythematous papules/ papulovesicles with occasional crusted lesions
B) same as A with ulcers
C) multiple red brown papules with some scale (more characteristic of PLC)
In Pityriasis Lichenoides: in terms of average length of disease activity how does diffuse distribution versus peripheral dist. change length??
Diffusely distributed represents shorter disease course generally with peripheral distribution lasting longer
Histological pathology/ description of pityriasis lichenoides
Dense cellular infiltrate (usually in the Dermis) → C
Epidermal focal Parakeratosis, occasional keratinocyte necrosis, mild erythrocyte extravasation (B)
A = chronic form of PLC, more prominent parakeratosis, less intense destruction of the epidermis
B = Acute PLEVA, scattered necrotic keratinocytes + parakeratosis, also note the extravasated erythrocytes in the dermis
DDX for PLEVA (Pityriasis Lichenoides Acuta
lymphatoid papulosis
cutaneous small vessel vasculitis
varicella, enteroviral exanthem
arthropod reaction
erythema multiforme
lichenoid drug eruption
folliculitis
dermatitis herpetiformis
Two types of parapsoriases: PLEVA and PLC (pityriasis lichenoides)
What are they
Adults or kids? male or female?
What are the suspicions of the pathogenesis?
Both have recurrent crops of spotneously regressing erythematous papules
Both are more prevalent in pediatric population, male predominance
Postulated to be a response to foreign antigens (infxn/ drugs), possible interaction with HIV/ Parvo B19, Meds (Estrogen/progesterone, TNF-Alpha inhibitors, statins, radiocontrast dye, maternal keratinocytes found in some patients (GVHD?)
PLEVA lesions crust and are occasionally vesiculopustular
PLC lesions are scaly
What is febrile ulcernecrotic mucha-habermann disease?
a variant of pityriasis lichenoides (PLEVA typically) that refers to diffuse involvement of the skin with confluent large, necrotic skin lesions with mucosal, GI, pulmonary involvement → increased TNF-A
Therapeutic ladder for pityriasis lichenoides
- Topical steroids
- topical coal tar
- oral erythromycin → tetracyclines → azithromycin
- Sunlight → UVB → PUVA
- MTX → cyclosporine
How is Pityriasis rubra pilaris (PRP) aquired?
Which gene is implicated?
Typically genetically, autosomal dominant most common, occasional A. Recessive
Gene: CARD14 aka PSORS2
Define the multiple, well described clinical features of CLASSIC PRP (pityriasis rubra pilaris)
Follicular hyperkeratosis on an erythematous base
Rough papules on the proximal fingers
Papules on the trunk - extremities that coalesce to form large salmon colored to orange-red plaques with “distinct - islands of sparing”
These coalescing plaques progress to an erythrodermic appearance with varying degrees of exfoliation
PALMS/ SOLES involved with a distinct orange-red waxy keratoderma
Scalp → erythema with a fine diffuse scale
Describe the lesions
A - Orange-red follicular papules coalescing into large scaly plaques with islands of sparing, obvious follicular hyperkeratosis
B - dorsal digits with clustered keratotic follicular papules
c - Salmon colored plaques with islands of sparing
D - erythrodermic with follicular accentuation of the scale
The most common form of PRP begins where and progresses ____
Are there typically symptoms?
How long does it last?
Beings on head/neck and progresses caudally
Commonly involves pruritus and burning
Type 1 classically lasts (accounts for >50% of all cases) less than 3 yrs
Type 2 PRP is classically seen as
palmoplantar keratoderma with a coarse/ lamellated scale and ichthyosiform scaling on extremities with occasional allopecia
In what age group is PRP type 3-5 seen in classically?
Juveniles/ adolescents
Type 3 PRP is similar to ___
When is peak onset?
The classic adult form type 1 and clears within 3 years
Peaks of onset in first 2 years of life and adolescence
Type 4 PRP
How common vs other forms
What is it like
Type 5 PRP is similar to ?
Type 4 is in juveniles with focal involvement, most common of the juvenile varieties
Type 5 is similar to type 2 as it has extremity involvement with follicular hyperkeratosis, erythema, scleroderma like changes of hands/feet -> Accounts for most familiar forms of PRP
Classic presentation of PR
How does it differ in presentation in darker skinned individuals?
Solitary lesion appears on trunk and enlarges over several days (herald patch)
The herald patch is pink-salmon-brown colored and is either a patch or plaque, slightly raised advancing margin, ranging from 2-4 cm but can be as large as 10 cm
Center has small fine scales, the long axis of lesions follows langer cleavage lines, on the back the lesion orientation follows a “christmas tree patterns”, occasional minute pustules can be seen
In dark skinned individuals : lesions tend to be more papular and hyperpigmented
Microscopic features of PR
Small mounds of parakeratosis, spongiosis and mild lymphohistiocytic perivascular interstitial papillary dermal infiltrate, sometimes mild erythrocyte extravasation and sometimes epidermal pustules
Bonus: Mounded parakeratosis differential
Pityriasis rosea-like eruptions: Triggered by medications or vaccinations
Guttate / eruptive psoriasis: May be very similar clinically and histopathologically
Herald patch is usually not present in psoriasis
Histopathologically: neutrophils present in the parakeratosis; dilated vessels in the papillary plates are more common with psoriasis
Secondary syphilis: Clinically, may be similar but no herald patch seen
Histopathologically: psoriasiform and lichenoid dermatitis with perivascular and interstitial infiltrate with lymphocytes, histocytes and plasma cells, the infiltrate may be granulomatous
Swollen, prominent endothelial cells are common ‘
Other eczematous eruptions (contact dermatitis, nummular dermatitis, seborrheic dermatitis):
May be indistinguishable histopathologically and clinical correlation is required, Although a few eosinophils may be present in pityriasis rosea, large numbers are uncommon
Drug eruptions:
Variable clinical presentation
Histopathology is variable; combination of interface pattern with spongiosis and eosinophil rich infiltrates are common
Pityriasis lichenoides:
Clinically, may have similar features; however, tends to have a chronic course, no herald patch present
Histopathologically: an interface dermatitis and perivascular lymphocytic infiltrate is present with erythrocyte extravasates
Presence of neutrophils in the parakeratosis
Type 1 pityriasis rotunda associations versus type 2 associations
What does the Path look like?
Type 1 is seen primarily in blacks/ asians and appears as large >10cm scaly, annular plaques/patch and is a/w internal malignancy (particularly hepatocellular/ gastric cancer) but no family history
Type 2 is seen in caucasians and is typically >30 smaller lesions with no fam history or a/w internal malignancy
Both are seen in adults 24-45 yo and there is slight female predominance
Most common in Mediterranean
May be a/w malnutrition, genetics
Path: looks like ichthyosis vulgaris, absent granular layer, moderate hyperkeratosis without parakeratosis, increased pigmentation of basal layer, epidermal atrophy
This variation of large plaque parapsoriasis has a rate of MF transformation of ___?
100% (possibly)
Retiform parapsoriasis - variant of large plaque para
widespread, ill-defined patches in net-like pattern
Ddx for small plaque parapsoriasis?
- Upper left- more common in children, often leaves behind PI hypopigmentation
- upper right- itchy!! more common in older population
- lower left- sudden onset of rash
- middle lower: pink, scaly papules and small plaques
- lower right- great mimicker, may have palm/sole involvement
Large plaque parapsoriasis Ddx :
Describe
Widespread papules with crust, some ulcerated, sometimes vesicles/ pustules
characteristic nail findings of LP include:
The characteristic nail abnormalities include lateral thinning (Fig. 11.15A), longitudinal ridging, and fissuring
Ddx for annular LP
Granuloma annulare (except LP has scale)
Porokeratosis
Tinea
Which two grey-brown rashes come to mind with LP variants
EDP
which skin types
describe morphology
Path?
treatment?
PLC Histology
Perakeratosis, mild basal layer vacuolization, predominantly superficial perivascular infiltrate , extravasated RBCs (less than pleva)
