spongiotic and psoriasiform reaction pattern and psoriasiform reaction pattern • dynamic prosess...

Spongiotic and psoriasiform reactionpattern

Boštjan LuzarInstitute of Pathology

Medical Faculty, Ljubljana, Slovenia

Spongiotic and psoriasiformreaction pattern

• Dynamic prosess• Different changes as the lesions evolve• Distinguishing clinical subtypes on histological

features frequently NOT possible• Patterns can overlap

– Some entities can have a variety of patterns(spongiotic and psoriasiform)

• Epidermis and dermis

Spongiotic reaction pattern

Spongiotic reaction pattern- Definition -

• Intraepidermal andintercellular edema(spongiosis)Widened

intercellularspaces Elongation of

intercellelarbridges

EARLY

Spongiotic reaction pattern

• Spongiosis Microscopic foci Vesicles Bullae DE juction

separation Crusting

• Exocytosis Lymphocytes Neutrophils Eosinophils

LATER

Pathogenesis of spongiosis

• Increased permeability of superficial vascularplexus– Immunological reactions– Direct damage– Unknown causes

• Increased hydrostatic pressure• Osmotic gradient towards the epidermis

Three phases of spongiotic dermatitis

• Acute• Subacute• Chronic

! There is a continuum of changes andhistological features frequently overlap

Acute spongiotic dermatitis- Changes in the epidermis -

• Stratum corneum retains normal basket-weave pattern

• Palor of keratinocytes• No acanthosis• Spongiosis

– Microvesicles

Acute spongiotic dermatitis

Acute spongiotic dermatitis- Changes in the dermis -

• Edema of the papillary dermis• Dermal perivascular inflammatory cell

infiltrate is variable Lymphocytes EosinophilsNeutrophils

Subacute spongiotic dermatitis

• Reactive changes of the epidermis Acanthosis (overlap with psoriasiform

pattern) Parakeratosis

• Granular layer may be diminished• Less spongiosis• Less dermal edema• Variable inflammation in the dermis, often

with eosinophils

Chronic spongiotic dermatitis

• Hyperkeratosis• Parakeratosis (with/without)• Acanthosis• No/little spongiosis• Granular layer thickened, irregular• Dermal inflammation mild• Dermal fibrosis can be present

Chronic spongiotic dermatitis

Conditions featuring spongiosis

• Eczema dermatitis family• Stasis dermatitis• Pityriasis rosea• Infections• Insect bite reaction• Polymorphous eruption of pregnancy• Erythema multiforme• Papular acrodermatitis of childhood• ....

Eczematous dermatitis = Eczema

• Clinical term• Group of disorders• Similar clinical features Moist Papules and plaques Vesicles Crust scale Erythematous base

• Similar histological features Spongiosis

• Frequently have different etiologies

Eczema- Background -

• Insufficiently distinct to reliably separate them onhistological grounds alone, clinical data vital

Spongiotic dermatitis, consistent with eczema

• Clinicians can subclassify on the basis of clinicalpresentation, history and possibly additional tests(e.g. allergic or irritant contact dermatitis, ...)

Eczematous dermatitis- Variants -

• Endogeneous– Atopic– Seborrheic– Discoid

(nummular)– Hand eczema– Autosensitization

(id) reaction

• Exogeneous– Contact– Infective– Asteatotic

Hand eczema(dyshidrotic eczema, pompholyx,

palmoplantar eczema)

Hand eczema (palmoplantar eczema)

• Recurrent pruritic vesiculareruption- Palms (70%)- Soles (10%)- Palms and soles (20%)- Digits (volar part, sides)

• Vesicles appear as smallpale papules

• Scaling, cracking• F>M

Hand eczema (palmoplantar eczema)- Pathogenesis -

• Idiopatic– Patients frequently have atopy– Majority of cases

• Allergic contact dermatitis– Drugs, shover gels, food, ...– Significant proportions

• Id-reactions

Hand eczema (palmoplantar eczema)

• Important to exclude dermatophyte infection(PAS stain)– ! The presence of neutrophils in the stratum

corneum

Contact dermatitis

Contact dermatitis

• Allergic Type IV hypersensitivity Exposure to specific antigen Poison ivy, latex, nickel, rubber, ...

• IrritantDirect damage of the epidermis 80% of the occupational skin diseasesDetergents, solvents, acids, alkalis, ...

Contact dermatitis- Clinical presentation -

• Erythematous plaues, papules and sometimesvesicles

• Distribution and shape of the lesion cansuggest etiology

Allergic contact dermatitis

Langerhans cell microabscesses

Eosinophilic granulocytescan be

scarce or absentin contact dermatitis.

Irritant contact dermatitis- Histological features

• Changes depend on the concentration of theoffending agent

• Pallor and ballooning of keratinocytes in theupper dermis

• Necroses of keratinocytes in variable numbers• Exocytosis of neutrophils in the area(s) of

ballooning and necrosis of keratinocytes

Discoid dermatitis(nummular eczema)

Discoid dermatitis (nummular eczema)- Clinical features -

• Single/multiple pruritic lesions• Usually starts as tiny papules or

papulovesicles– Confluence of lesions– Grouping in the shape of coins

• Surface wheeping and/or crusted• Margins usually flat

Discoid dermatitis (nummular eczema)- Clinical features -

• Sites of predilection– Lower legs– Forearms (extensor)– Dorsum of hands

• Two peak ages of onset– Young women– Middle aged adults

• Chronic course withremissions and relapses

Nummular dermatitis- Pathogenesis -

• Poorly understood• Related to atopy• As a consequence of allergy to

– Nickel– Cobalt– Chromate

• Can follow exposure to irritants– Soap, acid, alkalis

Nummular dermatitis- Histology -

• Acute/subacute/chronic spongiotic dermatitis• Progressive psoriasiform hyperplasia of the

epidermis, not as uniform as in allergic contactdermatitis

• Scale crust frequent• Dermal infiltrate contains lymphocytes,

occasional neutrophils, eosinophils andplasma cells

‘Specific’ forms of spongiotic dermatitis

• Stasis dermatitis• Pityriasis rosea• Vesicular dermatophytosis

! ALWAYS CORRELATE WITH CLINICAL HISTORY

Stasis (varicose) dermatitis

• Middle aged and older patients• Impaired venous return from lower limbs• Medial aspects of lower leg / ankle• Clinical presentation

- Oedema with shiny or erythematousappearance

- Dry, scaly, crusted erythematous orbrawnish discolorations

• Often around stasis ulcer(s)

Stasis (varicose) dermatitis

• Spongiosis and acanthosis• Lobular vascular proliferation

– Can be prominent with formation of papules• Hemosiderin

– Abundant, throughout the dermis• Fibrosis

– prominent in long-standing lesions• Inflammation (L, MF, PL)• Erythrocyte extravasation

Pityriasis rosea

Pityriasis rosea

• Acute self limited disease• F>M• 15-55 years (about 75% of patients)• Seasonal variations• Recurrent disease in < 5%

Pityriasis rosea

• Single red scalyplaque = heraldpatch

• Usually on the trunk• Increases in size

over 48 hours (2-10cm)

• Systemic symptomscan also be present

Pityriasis rosea

• Secondaryincubation periodof 7-14 days

• Generalizederuption oferythematousscaly lesions

• Chest, abdomen,thighs, arms, back

• Cause unknown

Pityriasis rosea- Histology -

• Subacute/chronic spongiotic dermatitis• Focal hyperkeratosis• (multi)focal parakeratosis• Slight irregular acanthosis• Vesiculation rare• Superficial perivascular mononuclear

inflammatory cell infiltrate• Extravasation of erythrocytes

!Neutrophils in the cornified layer are not a

feature of pityriasis rosea*

Consider guttate psoriasis*

Exclude infection

Spongiotic dermatitis- Secondary changes-

• Frequently becomes infected• Dramatic change in histopathologyMarked acute inflammationDevelopment of pustules

• Subcorneal• Intraepidermal• Subepidermal

• Additional stain(s) necessary

Psoriasiform reaction pattern


• Epidermalhyperplasia(acanthosis)

• Uniform andmarkedly enlargedrete ridges


• Psoriasis• Reiter’s syndrome• Pityriasis rubra pilaris• Pityriasis rosea• Lichen simplex chronicus• Psoriasiform drug eruptions• Subacute/chronic spongiotic dermatitis• Necrolytic migratory erythema• ....

Psoriasis vulgarisis

the prototype ofpsoriasiform dermatitis

Psoriasis vulgaris• Classic features Sharply demarcated erythematous plaques Silvery scaly surface

• Sites of predilection– Scalp– Extensor surfaces– Lower back– Periumbilical– Nails (pitting, distal onycholysis, ...)

• Granular layerabsent

Psoriasis vulgaris- Histology -

• Uniform acanthosis• Parakeratosis (prominent, confluent)• Diminished/absent granular layer• Collections of neutrophils in the epidermis• Thinning of suprapapillary plates• Papillary dermal vesselsDilated, congested Turtous

Eosinophilsare typically

ABSENTin psoriasis

If present, consider psoriasis-likeeczematous process, drug eruption, ...

*Classic psoriasis not difficult to

recognize*

Rarely biopsied*

Variants of psoriasis can be challenging

Evolving psoriasis- Histology -

• Epidermal changes– Mild initial spongiosis– Mild acanthosis– Focal parakeratosis– Mild lymphocyte exocytosis

• Dermal changes– Dilatation and congestion of superficial

vascular plexus– Mild perivascular lymphocytic infiltrate

Evolving psoriasis

Gutate psoriasis• Rapid onset of

numerous smallplaques and papules(0.5-1.5 cm)

• Upper trunk, proximalextremities

• Young patients• Often history of

antecedent pharyngitis(streptococcal)

Guttate psoriasis - histology

Histological features overlap with those ofevolving disease

Guttate psoriasis• Acanthosis much less marked• Parakeratosis FocalNeutrophils

• Focal loss/diminution of granular cell layer• Mild spongiosis• Superficial dermal inflammation

– Neutrophilic granulocytes, lymphocytes– No eosinophils!

Guttate psoriasis

Pustular psoriasis - generalized

• Fever of several daysduration

• Sudden appearance ofsterile pustules (2-3mm)

• Erythematous skin –progression toerythroderma

• Recurrent episodes offever and pustules

Pustular psoriasis - generalized

• Predisposing conditions– Infections (bacterial, viral)– Withdrawal of systemic steroid therapy– Drugs– Pregnancy– Hypocalaemia– Sunlight / phototherapy– Emotional stress– ...

Pustular psoriasis

A characteristichistological feature is

formation ofmacropustule(s)

Pustular psoriasis

• Large collections of neutrophils withinepidermis and/or stratum corneum

• Granular layerNormal Partially diminised

• No significant acanthosis due to the rapiddevelopment

Pustular psoriasis – dif. dg.

• Infection (fungi)Additional stains (PAS, ...)

• Generalized exentematous pustulosisHistory of new medications Eosinophis!!!

Pityriasis rubra pilaris


• Rare disease• Small follicular papules

(trunk)– Central keratin plug

• Erythema– Perifollicular

erythema– Confluent– Large expanding

plaques


• Islands of sparedskin

• Erythema hasorange-yellow tint

• Palmoplantarkeratoderma

Pityriasis rubra pilaris –non follicular lesions

• Checkerboard parakeratosis (alternating orthoand parakeratosis in horizontal/verticalfashion)

• Focal/confluent hypergranulosis• Marked uniform acanthosis• Broad rete ridges• Thick suprapapillary plates• Narrow dermal papillae

‘Shoulder parakeratosis’

Pityriasis rubrapilaris

• Follicular plugging


Can be confusedwith

psoriasison histology.


1. Lacks neutrophils in stratum corneumor epidermis

2. No suprapapillar plate thinning3. Granular layer not diminished

Pityriasis rubra pilaris - beware

1. Biopsies from early lesions can beinconclusive

2. Biopsies from follicular papules non-specific

Lichen simplex chronicus and prurigo nodularis

• Related entities• Result of persistent rubbing or scratching• Pruritic scaly plaques• Pruritic nodules• Ulceration secondary to excoriation


Onlyon areas

that patientcan

reach


Nape of the neckShin

ForearmsDorsal feet

Perianal / genital areas

Lichen simplex chronicus

• Prominent hyperkeratosis• Psoriasiform hyperplasia• Focal parakeratosis• Hypergranulosis


Fibrosis of papillary dermis characterised byvertically oriented

thick collagen fibres(vertical streaking)

Prurigo nodularis

• Pseudo-epitheliomatoushyperplasia

• Extension into hairfollicle

Spongiotic and psoriasiform reaction pattern- Conclusions -

• Dynamic prosess• Different changes as the lesions evolve• Distinguishing clinical subtypes on histological

features frequently NOT possible• Patterns can overlap• Clinico-pathological correlation crucial

spongiotic and psoriasiform reaction pattern and psoriasiform reaction pattern • dynamic prosess...

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