Inflammatory skin disease I Jade Wititsuwannakul, MD Chulalongkorn University, Thailand

Inflammatory skin disease I Jade Wititsuwannakul, MD Chulalongkorn University, Thailand

Superficial Perivascular Dermatitis Interface Dermatitis Vacuolar Dermatitis Lichenoid Dermatitis

Barnhill Textbook of Dermatopathology

Lichenoid Dermatitis ƒlichen planus ƒlichenoid drug eruption ƒlichen striatus ƒlichenoid photodermatitis ƒlichenoid GVHD ƒlichenoid purpura of Gougerot-Blum ƒlichen nitidus Lichenoid discoid lupus erythematosus

civatte bodies and pigmentary incontinence Requisites in dermatopathology

Lichen planus Prominent pruritus Violaceous polygonal papules and plaques Often grouped Surface may have white lines or grooves Wickham s striae May show Koebner phenomenon Flexural surfaces favored Oral and genital involvement common Nail changes with dystrophy, ridging, and splitting Associations with hepatitis C and B

Lichenoid

Requisites in dermatopathology

Histologic features Lichen planus Compact orthohyperkeratosis Lichenoid interface inflammatory infiltrate of lymphocytes and histiocytes May have melanophages in older lesions Basal zone vacuolar change with degenerated keratinocytes (Civatte bodies) Often epidermal acanthosis with saw-tooth pattern of rete ridges Wedge-shaped hypergranulosis

Lichenoid interface dermatitis With parakeratosis/ eosinophils Lichen planus-like keratosis ( LPLK ) or Benign lichenoid keratosis Lichenoid drug eruption Lichenoid GVHD Lichenoid photodermatitis

Lichenoid drug eruption Violaceous papular eruption with or without oral involvement Individual lesions resemble lichen planus Can progress to have a psoriasiform appearance Eruption develops in weeks to months Can be extensive Resolution following cessation of drug is slow Usually has post-inflammatory pigmentation

Lichenoid drug eruption Bandlike infiltrate hugs dermal-epidermal junction Mixed composition of infiltrate Lymphocytes, histiocytes, eosinophils, plasma cells Mid dermal perivascular inflammatory component Basilar vacuolar change with colloid body formation Patchy parakeratosis often seen May have granuloma formation Sulfa drugs, antibiotics, angiotensin-converting enzyme inhibitors, lipid-lowering agents, antihistamines, beta-blockers

LP vs. LP drug Feature LP LP Drug Parakeratosis - + Acanthosis ++ + Hypergranulosis ++ + Eosinophils /plasma cells + ++ Deep infiltrate - ++

LPLK

Lichenoid purpura Perivascular and interstitial mononuclear infiltrate Mild basal vacuolar change with rare necrotic cells Erythrocyte extravasation Hemosiderin deposition in late stage lesions No true vasculitis

Barnhill Textbook of Dermatopathology

Vacuolar Dermatitis Group of diseases that share in common Basal layer vacuolization Necrotic keratinocytes

Vacuolar Interface Dermatitis Erythema multiforme Toxic epidermal necrolysis Graft-versus-host disease Lupus erythematosus, acute Dermatomyositis Lichen sclerosus Pityriasis lichenoides Morbilliform drug eruption Radiation-induced dermatitis, subacute and chronic

Erythema multiforme Erythematous patches with dusky centers Target lesions Three zones bull s eye Peripheral rim of erythema Inner rim of pallor Central red macule Predilection for distal extremities but may be generalized Self-limited but often recurrent

Erythema multiforme Associated with HSV, medications, mycoplasma pneumonia Spectrum of disease severity Erythema multiforme Stevens-Johnson syndrome (with mucosal and conjunctival involvement) Toxic epidermal necrolysis (TEN)

Toxic Epidermal Necrolysis (TEN) Presents as diffuse painful erythema becoming dusky over time Often injection of mucosa and conjunctivae Progresses into generalized blistering and mucosal ulceration Sheets of sloughing skin with bleeding base Patients are generally systemically ill

Barnhill Textbook of Dermatopathology

Graft-versus-Host Disease Occurs after allogenic or autologous bone marrow transplantation, leukocyte-rich blood transfusion, or leukocyte-rich solid organ transplantation Acute and chronic phases

Barnhill Textbook of Dermatopathology

Grade 0 Acute Graft-versus-Host Disease: Grading no pathologic change or diagnosis unrelated to GVHD Grade 1 basal vacuolization Grade 2 basal vacuolization, necrotic keratinocytes, dermal inflammation Grade 3 confluence of basal vacuoles into cleft, spongiosis Grade 4 epidermal necrosis with separation of epidermis from dermis

Chronic Cutaneous Lupus Discoid Histologic Features Stratum corneum hyperkeratosis with follicular plugging Epidermis atrophy vacuolar interface degeneration with dead cells squamatization of the basal layer Basement membrane thickening and tortuosity in areas of severe hydropic change, can be fragmented

Chronic Cutaneous Lupus Histologic Features Dermis Discoid superficial and deep perivascular lymphomononuclear infiltrate which tends to involve pilosebaceous/ appendageal units can be interstitial along D-E junction mucin is increased edema, vasodilation, and slight RBC extravasation dermal melanophages Subcutis slight extension of the infiltrate can occur

630/57

Dermatomyositis Erythematous infiltrated plaques usually on the face but may be generalized Often periorbital erythema with violaceous hue heliotrope Poikiloderma Atrophic papules with scale on knuckles (Gottron s papules)

Lichen Sclerosus Erythematous patch or plaque often with edematous, pale, or white center Older lesions more indurated and atrophic Lesions may be localized or generalized Rare blistering form with hemorrhagic vesicle contents Occurs most often in the genital skin of woman but men and children can also be affected Balanitis xerotica obliterans

Pityriasis lichenoides et varioliformis acuta (PLEVA) Abrupt onset Widely distributed Any age but especially children and adolescents Crops of erythematous papules and necrotic vesicles Lesions resolve with dyspigmentation and scarring over several weeks

Pityriasis lichenoides et varioliformis acuta (PLEVA) Superficial and deep vascular infiltrate Confluent prarakeratosis Basal vacuolization and necrotic keratinocytes Band-like infiltrate or lichenoid changes

Pityriasis lichenoides chronica (PLC) Gradual onset Widely distributed Any age but especially children and adolescents Crops of erythematous papules 3 10 mm in diameter Lesions evolve to have dusky pinpoint center Rarely vesiculation or ulceration Lesions resolve with dyspigmentation over several weeks Usually no scarring

Pityriasis lichenoides chronica (PLC) Wafer-like parakeratotic scale Subtle basal layer vacuolization with occasional necrotic keratinocytes Superficial perivascular and lichenoid mononuclear infiltrate May have striking exocytosis of lymphocytes Erythrocyte extravasation

Barnhill Textbook of Dermatopathology

Spongiosis Epidermal Hyperplasia Spongiotic Dermatitis Psoriasiform Dermatitis

Psoriasiform dermatitis Diseases with psoriasiform epidermal hyperplasia as a characteristic feature Psoriasis Reiter s disease Lichen simplex chronicus Prurigo nodularis Pityriasis rubra pilaris Lamellar ichthyosis Inflammatory linear verrucous epidermal nevus (ILVEN) Pellagra Acrodermatitis enteropathica Necrolytic migratory erythema ( NME )

Psoriasis Chronic papulosquamous disorder Sharply circumscribed plaques with silvery micaceous scale Auspitz sign Koebner phenomenon Predilection for scalp, groin, extensor surfaces (elbows and knees), nails Inherited component (HLA-B13, HLA-Bw17)

Psoriasis: Clinical variants Psoriasis vulgaris (classic) Guttate (eruptive) Pustular Generalized pustular (von Zumbusch) Impetigo herpetiformis Erythrodermic

Psoriasis: Clinical variants Psoriasis vulgaris (classic) Symmetric distribution of sharply defined scaly plaques Guttate (eruptive) Represents approximately 2% of cases Common form in children May have preceding URTI (streptococcal) In adults may become chronic Pustular May be localized or generalized

Psoriasis: Clinical variants Impetigo herpetiformis Generalized pustular psoriasis in pregnancy Erythrodermic Diffuse skin involvement without discrete plaques Usually greater that 90% of body surface involved

Guttate

Pustular (acrodermatitis continua of Hallopeau)

Pustular (pustulosis of palms and soles)

Generalized pustular (von Zumbusch)

Impetigo herpetiformis

Erythrodermic

Guttate

1200/56

1200/56

1264/56

1264/56

Superficial perivascular dermatitis with epidermal spongiosis

Spongiotic Dermatitis General Principles Spongiosis = intercellular edema of the epidermis Mild: expanded intercellular spaces with accentuated intercellular bridges Marked: intraepidermal spongiotic vesicles Clinical correlate = eczematous dermatitis Mild erythema to oozing/weepy skin Scaly lichenified skin Subdivisions Eosinophilic spongiosis Follicular spongiosis Miliarial spongiosis

Spongiosis: definition Widening of the space between epidermal keratinocytes due to intercellular edema.

Spongiosis: pathogenesis Permeation of the epidermis and dermis by inflammatory cells and fluid (plasma transudate). Edema of papillary dermis and edema between epidermal keratinocytes. Keratinocytes damage and vesicle formation.

Spongiotic Dermatitis: Clues to Differential Diagnosis Composition of cellular infiltrate Presence of parakeratosis (scale) Quality of scale Presence or absence of epidermal hyperplasia Localization of spongiosis Presence or absence of papillary dermal changes

Spongiotic Dermatitis Allergic contact dermatitis Nummular dermatitis Id reaction Dyshidrotic dermatitis Dermatophyte infection, vesicular Pityriasis rosea Erythema annulare centrifugum, active border Seborrheic dermatitis, acute Irritant dermatitis, acute Stasis dermatitis

Exocytosis : inflammatory cells infiltrate within epidermis Serum exudate Spongiosis : intercellular edema Papillary dermal edema Inflammatory cells infiltrate within dermis

Spongiotic dermatitis (a tissue reaction pattern) Eczematous process: contact dermatitis, atopic dermatitis, nummular dermatitis, Id reaction Acute dermatitis Subacute dermatitis Chronic dermatitis Pityriasis rosea Seborrheic dermatitis Stasis dermatitis Erythroderma

Subacute dermatitis by metal : scaly papules, plaques Derm101.com Acute dermatitis by Rhus plant : papules, vesicles Derm101.c Chronic dermatitis by eyedrops : lichenified plaques

Acute dermatitis: prominent spongiosis

Subacute dermatitis: psoriasiform spongiotic

Chronic dermatitis: psoriasiform

Derm101.co Acute dermatitis Excessive fluid within dermal papilla, extending into the epidermis. Intercellular edema. Microvesicle formation.

Basket-weave stratum corneum Spongiosis : intercellular edema Intraepidermal microvesicles Lymphocytes exoxytosis Inflammatory cells infiltrate Yu-Hung Wu M.D. 149/156 Acute eczematous process: spongiotic dermatitis

Features of acute dermatitis Basket-weave stratum corneum Lymphocyte, neutrophils (secondary) exocytosis Spongiosis, intraepidermal microvesicles Serum crust, exudate Langerhans cell microabscess Papillary dermal edema Dilatation of blood vessels with prominent endothelial cells Perivascular lymphocytes and/or eosinophils infiltrate.

Acute spongiotic pattern Normal stratum corneum Normal epidermal thickness Spongiosis mild to marked, often with vesicle formation Eosinophils and lymphocytes Allergic contact dermatitis Irritant contact dermatitis Dyshidrotic dermatitis Photoallergic dermatitis Id reaction Incontinentia pigmenti (stage I) miliaria

Subacute dermatitis After days of inflammation Stratum corneum becomes more compact with parakeratosis. Increased thickness of spinous layer (acanthosis, psoriasiform hyperplasia) Less spongiosis than acute dermatitis. Psoriasiform spongiotic dermatitis. Derm101.com

Subacute spongiotic pattern Parakeratotic stratum corneum Epidermal acanthosis/thickening Spongiosis mild to moderate Lymphocytes and sometimes eosinophils Nummular dermatitis Pityriasis rosea Seborrheic dermatitis Dermatophytosis Erythema annulare centrifugum

Compact stratum corneum Parakeratosis Hypergranulosis Serum exudate Hypogranulosis Mild spongiosis & lymphocytes exocytosis Acanthosis Papillary edema & blood vessels dilatation Subacute eczematous process: psoriasiform spongiotic dermatitis

Chronic dermatitis After weeks of inflammation Stratum corneum becomes more thick and compact with/without parakeratosis. Increased granular cell layer (hypergranulosis). Increased thickness of spinous layer (acanthosis, psoriasiform hyperplasia). Papillary dermal fibrosis. Psoriasiform dermatitis. Derm101.com

Chronic spongiotic pattern Hyperkeratotic, parakeratotic stratum corneum Moderate to marked epidermal acanthosis Spongiosis minimal to absent Lymphocytes Dermal fibrosis Lichen simplex chronicus Prurigo nodularis

Compact hyperkeratosis Focal parakeratosis Hypergranulosis Mild to minimal spongiosis Papillary dermal fibrosis Irregular acanthosis Chronic eczematous process: psoriasiform dermatitis