Paul K. Shitabata, M.D. Dermatopathology Institute · Allergic contact dermatitis Nummular dermatitis Dyshidrotic dermatitis Id reaction Photoallergic dermatitis, early Dermatophytosis

Paul K. Shitabata, M.D.Dermatopathology Institute

Patterns

Epidermis

Dermis/Vessels/Hair Follicles

Fat/Vessels

Diagnosis!

Epidermis Dermis

Vessels Fat

Epidermal Reaction PatternsOrthokeratosis

Spongiosis

AcanthosisParakeratosis

Hyperkeratosis

Modify by Inflammatory Cell

type

Spongiosis

Parakeratosis Acanthosis Hyperkeratosis

Orthokeratosis

Hyperkeratosis Acanthosis

Epidermal/DermalReaction Patterns Superficial perivascular Superficial and deep perivascular Nodular and diffuse Intraepidermal vesicular and pustular Subepidermal vesicular

Epidermal ChangesSpongioticBallooning

Psoriasiform/Lichenoid

Epidermal Changes Interface

No Epidermal ChangesPerivascular

Intestitial

Superficial/Deep

Lichenoid/Interface

Psoriasiform

Psoriasiform Lichenoid

Spongiotic

Superficial Perivascular No Epidermal Changes

Tinea versicolorDermatophytosis ErythrasmaPitted keratolysis Vitiligo Schamberg's disease Viral exanthemsDrug eruption (one type)Urticaria, lateErythema figuratum, superficial

Superficial Perivascular/Interstitial No Epidermal Changes

Schamberg's diseasePUPPP

Dermatitis herpetiformisLinear IgA dermatosisDermatitis herpetiformis-like drug eruptionsAcute discoid lupus erythematosus/SLELeukocytoclastic vasculitisErythema marginatum

Superficial Perivascular/Interstitial No Epidermal Changes

Bullous pemphigoid/Herpes gestationis, urticarialPemphigus vulgaris, urticarialArthropodPUPPP

Urticaria Postinflammatory

pigmentary alterationMacular amyloidosis

Urticaria pigmentosaBrachioradial pruritis

Superficial Perivascular Psoriasiform

PsoriasisAllergic contact dermatitisNummular dermatitisDyshidrotic dermatitis Pityriasis rubra pilaris Seborrheic dermatitis

Superficial Perivascular Psoriasiform

Dermatophytosis Candidiasis

Lichen simplex chronicusPrurigo nodularisAcanthoma fissuratumPressure papule from prosthesisSurfer's nodulesChondrodermatitis nodularis helicis

Superficial PerivascularSpongiotic Psoriasiform

Allergic contact dermatitis

Nummular dermatitisDyshidrotic dermatitisId reactionSeborrheic dermatitis

Nonbullous congenital ichthyosiform erythroderma Lichen striatus

Superficial PerivascularLichenoid/Interface

Lichen planusLichenoid drugPityriasis lichenoides chronica

DLEDermatomyositisGVHEM

Superficial PerivascularPsoriasiform/Lichenoid

Lichen striatusBullous pemphigoidHerpes gestationis, urticarial

Mycosis fungoides

Superficial/DeepNo Epidermal Changes

Polymorphous light eruption, earlyErythema figuratumErythema chronicum migransPernio

Erythema nodosum PMLE DLE, tumid CLL

B-cell lymphoma

Superficial/DeepNo Epidermal Changes

Arthropod insult Erythema chronicum migrans

Scleroderma Leprosy, indeterminate

Superficial/Deep Perivascular and Interstitial

Suppurative folliculitis, periphery

Neutrophilic eccrine hidradenitis

Flea bite Cellulitis Erythropoietic protoporphyria Arthropod Erythema chronicum migrans Well's syndrome

Superficial/Deep Perivascular and Interstitial

Granuloma annulare Necrobiosis lipoidica Interstitial granulomatous

dermatitis with arthritis Mycosis fungoides,

granulomatous

Superficial/Deep Epidermal Lichenoid-Interface

PLEVAFixed drug eruptionDermatophytosis

LyPGVHDLE

Acrodermatitis chronica atrophicans

Mycosis fungoides, plaque

Nodular/Diffuse DermatitisLymphocytes

Histiocytes (Granulomas)

EosinophilsPlasma cells

Neutrophils

Nodular/Diffuse Dermatitis Histiocytes

(Granulomas) Sarcoidal Tuberculoid Palisaded Suppurative

Nodular/Diffuse Dermatitis Histiocytes

(Granulomas) Tuberculoid Suppurative

Nodular/Diffuse DermatitisCell Type Diagnosis

Neutrophils Sweets

Eosinophils Well’s, Hypersensitivity

Plasma cells Lyme disease

Histiocytes Granulomatous diseases

Mixed Granuloma faciale

Intraepidermal Vesicular and Pustular Dermatitis

Vesicular Pustular

Ballooning Spongiosis Acantholysis Cleaving Intracorneal Subcorneal

Intraepidermal Vesicular Dermatosis

Spongiosis

Intraepidermal vesicle

Intraepidermal bullae

Intraepidermal Spongiosis Allergic contact dermatitis

Nummular dermatitisDyshidrotic dermatitis

Id reactionPhotoallergic dermatitis, earlyDermatophytosisMiliaria rubra Gianotti-Crosti syndrome Pityriasis roseaErythema annulare centrifugum Seborrheic dermatitis

Lichen striatus Pityriasis alba

Mycosis fungoides, macule/patch

Intraepidermal Spongiosis PUPPP

Allergic contact dermatitisNummular dermatitisDyshidrotic dermatitis

Id reaction Bullous pemphigoidHerpes gestationisPemphigus vulgaris, urticarial Incontinentia pigmenti

Toxic erythema of newborn Arthropod assault

Intraepidermal Ballooning Herpes

OrfParapox infection

Measles Hydroa

aestivale/Hydroa vacciniforme

Intraepidermal with Acantholysis Pemphigus vulgaris

Pemphigus vegetansPemphigus erythematosusPemphigus foliaceusFogo selvagem

Grover’s disease

IntraepidermalSpongiotic Psoriasiform/Lichenoid

Allergic contact dermatitis Nummular dermatitis Dyshidrotic dermatitis Id reaction Seborrheic dermatitis Nonbullous congenital

ichthyosiform erythroderma Lichen striatus

IntraepidermalSpongiotic Psoriasiform/Lichenoid

Lichen striatus Bullous pemphigoid Herpes gestationis, urticarial MF

Subepidermal Vesicular Dermatosis

Subepidermal

Minimal Mixed Lymphocytes

Neutrophils Neuts/Eos Mast Cells

Subepidermal Vesicular Dermatosis Bullous pemphigoid/Herpes

gestationis Cicatricial pemphigoid Dermatitis

herpetiformis/Linear IgA disease

Subepidermal Vesicular Dermatosis EBA Bullous LE Bullous mastocytosis Bullous amyloidosis Drug reactions LP

Special Categories Vasculitis Alopecia Folliculitis/Perifolliculitis Fibrosing dermatitis Panniculitis

Vasculitis

Mixed

Large Vessel

Small Vessel

Vasculitis Leukocytoclastic

vasculitis Microscopic arteritis Polyarteritis nodosa Erythema induratum

Alopecia

Non-Inflammatory Inflammatory

Follicle density normal Follicle density decreased Lymphocytes Mixed

AlopeciaNon-Inflammatory

Follicle density normal Androgenic alopecia

Telogen effluviumTrichotillomania

Follicle density decreased Traction alopecia

AlopeciaInflammatory

Alopecia areataLichen planopilaris DLEScleroderma

Folliculitis decalvansTinea capitisMajocchi's granuloma Burns/Radiation

Syphilis Scar

LPPSclerodermaDLE

Spongiotic

PerifolliculitisSuppurative

Folliculitis

Granulomatous Fibrosing

Lymphocytes

Perifolliculitis

Folliculitis/Perifolliculitis Infectious (Staph, Strep,

DermatophytosisEndothrix/Ectothrix)

Acne vulgarisAcne rosaceaPerforating disorders

Folliculitis/Perifolliculitis Infundibulofolliculitis

Alopecia mucinosa Perifolliculitis

ScurvyLichen planopilarisDLERosaceaKeratosis pilaris

Fibrosing DermatitisFibrosing Dermatitis

Fibrocytes Increased Fibrocytes Decreased

SclerosisRadiation

ScarScleroderma/Morphea

Antecedents to Fibrosis

UlcerGranulation tissue

Granulomas

Sclerosis

Fibrosis

Antecedent to Fibrosis

Fibrosing Dermatitis Scar Chronic lymphedema Keloid Dermatofibroma Anetoderma Acrodermatitis

chronica atrophicans LSEA/Morphea Radiation sclerosis

Panniculitis

LobularWith or without Vasculitis

SeptalWith or without vasculitis

Panniculitis Erythema nodosum

Erythema induratum Lupus panniculitis

InfectiousPancreatic fat necrosisLympohmaSubQ fat necrosisPoststeroid panniculitis

Questions People talk

fundamentals and superlatives and then make some changes of detail.

Oliver Wendell Holmes Jr. (1841 - 1935)