Morphology of skin lesionsMorphology of skin lesionsDr Mesfin HunegnawDr Mesfin Hunegnaw

Consultant Dermatologist & VenerologistConsultant Dermatologist & Venerologist

AAU, Medical facultyAAU, Medical faculty

Dept. of DermatovenerologyDept. of Dermatovenerology

Morphology of skin lesionsMorphology of skin lesions

Includes:Includes: Type of the lesion,Type of the lesion, Size of the lesion,Size of the lesion, Shape of the lesion,Shape of the lesion, Distribution and arrangement,Distribution and arrangement, Margination.Margination.

Leads to Leads to DIAGNOSIS.DIAGNOSIS.

Types of skin lesions…Types of skin lesions…

Generally;Generally;-Asymmetrical- exogenous cause,-Asymmetrical- exogenous cause,

-Symmetrical- endogenous cause.-Symmetrical- endogenous cause.

Exantum:Exantum: widespread cutaneous eruption, widespread cutaneous eruption,

Enantum:Enantum:when there is mucosal involvement.when there is mucosal involvement.

ClassificationClassification

Primary:Primary:--The original uncomplicated patternThe original uncomplicated pattern Macule, papule, nodule, pustule, vesicle, bullae, wheals, Macule, papule, nodule, pustule, vesicle, bullae, wheals,

erythema.erythema.

Secondary:Secondary:--With further development like infection, trauma, With further development like infection, trauma,

treatment…treatment… Scale, plaque, crust, fissure, erosion, ulcer, scar, Scale, plaque, crust, fissure, erosion, ulcer, scar,

lichenification, atrophy. lichenification, atrophy.

Primary skin lesions:Primary skin lesions:

1-Macule:1-Macule: ‘‘macula’: ‘spot’macula’: ‘spot’ Flat, change in skin colour,Flat, change in skin colour, No elevation or depression,No elevation or depression, Not identified by mere touch,Not identified by mere touch, <1.0 cm= macule,<1.0 cm= macule, >1.0cm>1.0cmpatch.patch.

Macule…Macule…

As a result of:As a result of: Hyper pigmentationHyper pigmentation - Cafe-au-lait spots,- Cafe-au-lait spots, - Post inf. hyper pigmentation.- Post inf. hyper pigmentation. Hypo pigmentationHypo pigmentation - post inf. Hypopigmentation,- post inf. Hypopigmentation, - Leprosy,- Leprosy, - Vitiligo.- Vitiligo.

Macule…Macule…

Vascular abnormalityVascular abnormality - Erythema Vs pupura- Erythema Vs pupuraMacules + fine scales= maculosquamousMacules + fine scales= maculosquamous - P.versicolor- P.versicolor - P.rosea- P.rosea TelangiectasiaTelangiectasia: permanent dilatation of : permanent dilatation of

capillariescapillaries

PurpuraPurpura

Macules of café au lait spots in NFMacules of café au lait spots in NF

Patch of vitiligoPatch of vitiligo

Patch of leprosy in 27 yrs EthiopianPatch of leprosy in 27 yrs Ethiopian

Patch of leprosy in 43 yrs EthiopianPatch of leprosy in 43 yrs Ethiopian

TelangectasiaTelangectasia

2-Papule2-Papule ‘‘Papula’: ’pimple’Papula’: ’pimple’ Small solid elevation,Small solid elevation, Most of the its part is above the plane unlike nodule,Most of the its part is above the plane unlike nodule, <0.5cm in diameter,<0.5cm in diameter, Epidermal, dermal or combined changes.Epidermal, dermal or combined changes.

Papule…Papule…

Epidermal:Epidermal: epidermal thickening, hyperkeratosisepidermal thickening, hyperkeratosis

-Wart-Wart

-Epidermal nevus-Epidermal nevus Dermal papuleDermal papule

-Syringoma-Syringoma

-Hemangiomas-Hemangiomas

-Neurofibromas…-Neurofibromas… Mixed papuleMixed papule

-Hypertrophic lichen planus…-Hypertrophic lichen planus…

Papule…Papule…

Can have d/t shape, colorCan have d/t shape, color - Flat-topped: LP…- Flat-topped: LP…

- Dome shaped: MC, fox Fordyce..- Dome shaped: MC, fox Fordyce..

- Pointed : Miliaria rubra- Pointed : Miliaria rubra

Can have d/t shape, colorsCan have d/t shape, colors Red papule: Rosacea, Acne fulminance folliculitis…Red papule: Rosacea, Acne fulminance folliculitis… Purple: LP…Purple: LP… Skin colouredSkin coloured: : lichen nitidus, Keratosis pilaris…lichen nitidus, Keratosis pilaris…

Keratosis pilarisKeratosis pilaris

MCMC

DPN in 48 yrs old Ethiopian DPN in 48 yrs old Ethiopian

Papules of SMx in 25yrs EthiopianPapules of SMx in 25yrs Ethiopian

Papules of mastocytosis in 1 yr EthiopianPapules of mastocytosis in 1 yr Ethiopian

Same…Same…

3-Nodule3-Nodule ‘‘Nodulus’: ‘small knot’Nodulus’: ‘small knot’ Palpable, solid, round lesion (big papule).Palpable, solid, round lesion (big papule). Felt > seen.Felt > seen. According to anatomy:According to anatomy: -Epidermal….Verruca vulgaris,-Epidermal….Verruca vulgaris, -Epidermo-dermal: Melanoma,-Epidermo-dermal: Melanoma, -Dermal: dermato-fibroma,-Dermal: dermato-fibroma, -Dermal-SC: Granuloma annulare-Dermal-SC: Granuloma annulare -SC: lipoma.-SC: lipoma.Can have different consistency: hard/soft.Can have different consistency: hard/soft.Color and shape can also be different.Color and shape can also be different.

??

SC nodulesSC nodules

Keloid noduleKeloid nodule

Nodules of leprosy in 45 yrs EthiopianNodules of leprosy in 45 yrs Ethiopian

4-Blister (vesicle, bullae)4-Blister (vesicle, bullae)

‘‘Vesicula’- ‘little bladder’Vesicula’- ‘little bladder’ ‘‘Bulla’- ‘bubble’Bulla’- ‘bubble’ Vesicle: small raised fluid filled lesion;<0.5cm in Vesicle: small raised fluid filled lesion;<0.5cm in

diameter.diameter. Bullae:> 0.5cm in diameter.Bullae:> 0.5cm in diameter. Cleavage at various levels of superficial skin.Cleavage at various levels of superficial skin.

Blister…Blister… Cleavage can be due to:Cleavage can be due to: -Intracellular edema—HS-Intracellular edema—HS( herpes simplex)( herpes simplex)

-Intercellular edema—ACD-Intercellular edema—ACD(allergic contact dermatitis)(allergic contact dermatitis)

-Acantholysis--P.vulgaris -Acantholysis--P.vulgaris (pemphigus vulgaris)(pemphigus vulgaris)

According location of cleavage:According location of cleavage: -Subcorneal: Impetigo, Subcorneal pustulosis…-Subcorneal: Impetigo, Subcorneal pustulosis… -Intraepidermal: P.vulgaris -Intraepidermal: P.vulgaris -Subepidermal: B.pemphigoids-Subepidermal: B.pemphigoids -Dermal: Dystrophic epidermolysis bullosa.-Dermal: Dystrophic epidermolysis bullosa.

Blister….Blister….

According to contentAccording to content:: -Fluid: p.vulgaris-Fluid: p.vulgaris

-Pus: impetigo-Pus: impetigo

-Blood: B.pemphigoids-Blood: B.pemphigoids

Photo toxic blistersPhoto toxic blisters

HZHZ

HZ in 32 yrs Ethiopian pt with HIVHZ in 32 yrs Ethiopian pt with HIV

HSHS

HZHZ

5-Pustule5-Pustule

Small pus containing swelling.Small pus containing swelling. Usually ass. with infection—from papules or vesiclesUsually ass. with infection—from papules or vesicles But they may But they may develop by their own—acne, non develop by their own—acne, non

pyogenic bacteriapyogenic bacteria Can be sterile---Can be sterile---pustular psoriasispustular psoriasis..

pustulespustules

Pustular plantar psoriasisPustular plantar psoriasis

Pustules & plaques in 33 yrs EthiopianPustules & plaques in 33 yrs Ethiopian

Palmoplantar pustulosis in Ethiopian pt.Palmoplantar pustulosis in Ethiopian pt.

6-Wheal6-Wheal

Also called urticaria,Also called urticaria, Round or flat topped red, purple papule/plaque that Round or flat topped red, purple papule/plaque that

disappears in a day or twodisappears in a day or two Due to edema in the upper dermis.Due to edema in the upper dermis. If lower SC = AngioedemaIf lower SC = Angioedema

insect biteinsect bite

WhealWheal

7-Scale (squames)7-Scale (squames)

‘‘Squama’ – ‘scale’Squama’ – ‘scale’ Flakes of stratum corneumFlakes of stratum corneum Increased Rate of production of epidermal cells and the Increased Rate of production of epidermal cells and the

outermost desquamation layers of skinoutermost desquamation layers of skin scale scale

scalesscales

Types of scalesTypes of scales -Pityriasiform-Pityriasiform: fine, bran-like: P.versicolor: fine, bran-like: P.versicolor -Psoriasiform-Psoriasiform: white, silvery, non-adherent : white, silvery, non-adherent psoriasis.psoriasis. -Ichthiosiform-Ichthiosiform: large discrete : large discrete Ichthiosis.Ichthiosis. -Collarete-Collarete: scales surrounding lesions: scales surrounding lesions -Inward pointing scales: P.rosea,-Inward pointing scales: P.rosea, -Trailing scales: EAC -Trailing scales: EAC

Psoriasis scalesPsoriasis scales

Psoriatic scale in 32 yrs Ethiopian ptPsoriatic scale in 32 yrs Ethiopian pt

P.rosea scalesP.rosea scales

Scales, IchthiosisScales, Ichthiosis

8-Plaque8-Plaque

Well defined plateau like elevation Well defined plateau like elevation Confluent papules… Psoriasis, LPConfluent papules… Psoriasis, LP

Plaque,LSCPlaque,LSCLichen simplex chronicus

Psoriatic plaquePsoriatic plaque

Plaques of keloids in 42 yrs EthiopianPlaques of keloids in 42 yrs Ethiopian

Plaques of leprosy in 42 yrs EthiopianPlaques of leprosy in 42 yrs Ethiopian

Plaque of Leprosy in 44 yrs EthiopianPlaque of Leprosy in 44 yrs Ethiopian

Plaque of Leprosy in 18 yrs EthiopianPlaque of Leprosy in 18 yrs Ethiopian

Plaques of Leprosy in 18 yrs EthiopianPlaques of Leprosy in 18 yrs Ethiopian

9-Crust9-Crust

‘‘Crusta’-’bark, shell’Crusta’-’bark, shell’ Serum, blood, purulent exudates dries on the skin Serum, blood, purulent exudates dries on the skin

surfacesurface

- Clear, yellow: serum.- Clear, yellow: serum.

- Yellow-green: purulent exudate…impetigo- Yellow-green: purulent exudate…impetigo

- Brown, dark red: blood.- Brown, dark red: blood.

HZ,crustHZ,crust

Impetigo,crustImpetigo,crust

Crusts in Ethiopian ptCrusts in Ethiopian pt

Crusts in Ethiopian ptCrusts in Ethiopian pt

Crusts in Ethiopian ptCrusts in Ethiopian pt

Crusts in Ethiopian ptCrusts in Ethiopian pt

10-Lichenification10-Lichenification

Grouped papules asso. with exaggeration Grouped papules asso. with exaggeration of skin markings and thickening: eg.of skin markings and thickening: eg.LSCLSC..

Lichenified eczemaLichenified eczema

11-Erosion, ulcer, wound11-Erosion, ulcer, wound Different types of tissue loses varying in their depth and Different types of tissue loses varying in their depth and

breadthbreadth

11.1-Erosion:11.1-Erosion:

- Superficial loss of tissue- Superficial loss of tissue

- Confined to the epidermis- Confined to the epidermis

- Wide>depth- Wide>depth

- No scaring- No scaring

Can occur in: Ruptured blister, Can occur in: Ruptured blister,

22ndnd degree burn… degree burn…

11.2-Ulcers11.2-Ulcers ‘‘Ulcus’- ’sore’Ulcus’- ’sore’ Larger defect involving the dermis and SCLarger defect involving the dermis and SC Occurs in damaged skinOccurs in damaged skin Slow healer, always scarSlow healer, always scar

-3-3rdrd degree burn degree burn

-Decubitus ulcer-Decubitus ulcer

11.3-Wound11.3-Wound Traumatic defect in normal skinTraumatic defect in normal skin Heals rapidly, less scaringHeals rapidly, less scaring

-Injury-Injury

-Surgery-Surgery

Erosion.pemphigusErosion.pemphigus

ulcerulcer

Ethiopian pt with ulcerEthiopian pt with ulcer

Erosions in Ethiopian pt with SSSSErosions in Ethiopian pt with SSSS

Erosions, Crusts & bullae in Ethiopian ptErosions, Crusts & bullae in Ethiopian pt

12-Excoriation, fissure12-Excoriation, fissure

12.1-Excoriation12.1-Excoriation Small superficial defect at epidermis, papillary dermis,Small superficial defect at epidermis, papillary dermis, Local trauma Local trauma scratching scratching itchy skin conditionsitchy skin conditions

12.2-Fissures12.2-Fissures Deep linear lesionsDeep linear lesions -T.ungum-T.ungum -Intertrigo-Intertrigo

ExcoriationsExcoriations

Ethiopian pt with PPEEthiopian pt with PPE

Ethiopian pt with PPEEthiopian pt with PPE

Ethiopian pt ?Ethiopian pt ?

14-Scar14-Scar

Happens when tissue defect is healed by fibrous tissue Happens when tissue defect is healed by fibrous tissue replacementreplacement

Can be :Flat Can be :Flat good surgery good surgery Depressed Depressed acne acne ((Ice peak scar,Boxcar scar,Rolling scarIce peak scar,Boxcar scar,Rolling scar))

Elevated Elevated hypertrophic hypertrophic

keloid keloid

15-Atrophy15-Atrophy

Thinning of the skin.. Epidermis, dermis or both Thinning of the skin.. Epidermis, dermis or both Epidermal : Thinning of epidermisEpidermal : Thinning of epidermis Transparent—visible vesselsTransparent—visible vessels Loss of skin textureLoss of skin texture Dermal: loss of CTDermal: loss of CT : Depression : Depression

Atrophy,steroidAtrophy,steroid

II-DistributionII-Distribution

Area of predilectionArea of predilection

Can be :Can be : LocalizedLocalized Widespread/disseminated :Chicken poxWidespread/disseminated :Chicken pox Diffuse—involving wider area with no intervening Diffuse—involving wider area with no intervening

normal skin: erysipelas normal skin: erysipelas

III-ArrangementIII-Arrangement

Solitary Vs multipleSolitary Vs multiple Multiple ones : grouped Vs random arrangementMultiple ones : grouped Vs random arrangement Grouped: HS, DH…Grouped: HS, DH… Linear: epidermal nevusLinear: epidermal nevus Segmental….HZSegmental….HZ Follow skin folds……P.roseaFollow skin folds……P.rosea

Grouped lesions.HSGrouped lesions.HS

Epidermal naevus, linearEpidermal naevus, linear

Linear arrangement,HZLinear arrangement,HZ

IV-SizeIV-Size

Exact measurement of the lesions on Exact measurement of the lesions on cm or mmcm or mm

Two perpendicular diameters –one Two perpendicular diameters –one representing the max. lesion sizerepresenting the max. lesion size

V-MarginsV-Margins

Border of the lesionBorder of the lesion Sharp Vs indistinctSharp Vs indistinct Active/scaly----fungal infn.Active/scaly----fungal infn.

Raised margins, granuloma Raised margins, granuloma annulare.annulare.

VI-ShapeVI-Shape

RoundRound OvalOval PolygonalPolygonal SerpiginousSerpiginous PolycyclicPolycyclic AnnularAnnular UmblicatedUmblicated

Clinical and laboratory aids to Clinical and laboratory aids to dermatologic diagnosisdermatologic diagnosis

Clinical signs:Clinical signs:

Dimple signDimple sign -Dermatofibrosis Vs malignant melanoma-Dermatofibrosis Vs malignant melanoma

Auspitz’s signAuspitz’s sign -psoriasis-psoriasis

Nikolsky’s signNikolsky’s sign --Acantholytic disorders…pemphigus, SSSS,TENAcantholytic disorders…pemphigus, SSSS,TEN

Darier’s signDarier’s sign -Urticaria pigmentosa -Urticaria pigmentosa

Clinical testsClinical tests Patch testPatch test -Allergic contact dermatitis-Allergic contact dermatitis -Identify the allergen-Identify the allergen Photo patch testingPhoto patch testing -To determine photo allergy-To determine photo allergy Prick testingPrick testing -Determine type 1 allergy-Determine type 1 allergy Aceton whitingAceton whiting -Sub clinical penile or vulvar warts, 5% acetic acid-Sub clinical penile or vulvar warts, 5% acetic acid Photo testingPhoto testing -Which WL of UVR causing photo induced illness: PMLE, AP, -Which WL of UVR causing photo induced illness: PMLE, AP,

HV…HV…

InstrumentalInstrumentalMagnificationMagnification Hand lensHand lens: better, closer visualization: better, closer visualization - LP- LP wickham's strea wickham's strea - SLE- SLE follicular pluging and atrophy follicular pluging and atrophy - Scabies-mite- Scabies-mite

DiascopyDiascopy -Glass spatula-Glass spatula -Lab. Slides-Lab. Slides Erythma Vs purpuraErythma Vs purpura

Instrumental…Instrumental… Wood’s lampWood’s lamp -Uses black light-Uses black light -Hair, skin diseases-dermatophytes of the hair shaft-Hair, skin diseases-dermatophytes of the hair shaftP.versicolour, Erythrasma…P.versicolour, Erythrasma… -Urine exam for porphyria-Urine exam for porphyria UltrasoundUltrasound -Penetrate 2-3mm-Penetrate 2-3mm -Ass. skin thickness—sceleroderma-Ass. skin thickness—sceleroderma -Ass of effect of steroids on the skin-Ass of effect of steroids on the skin -Flow of blood-Flow of blood PhotographyPhotography

MicroscopyMicroscopy

KOH:KOH: different fungal infections different fungal infections Gram stainGram stain with culture and sensitivity with culture and sensitivity Dark field:Dark field: T.pallidum detection. T.pallidum detection. Tzank preparation:Tzank preparation: HS,HZ HS,HZ

Gaint multinuclated cells,Gaint multinuclated cells, Wet mount,Wet mount, Indian ink…Indian ink…

HistopathologyHistopathology

Routine histologyRoutine histology Immunoflorescent microscopyImmunoflorescent microscopy ImmunohistochemistoryImmunohistochemistory Electron microscopeElectron microscope

SerologySerology

Used for evaluation of infectious and Used for evaluation of infectious and autoimmune diseasesautoimmune diseases

BiopsyBiopsy Doubt about diagnosis-biopsy should be doneDoubt about diagnosis-biopsy should be done The slightest doubt that a lesion could be a malignancy The slightest doubt that a lesion could be a malignancy

is an indication for biopsyis an indication for biopsy Area: fresh lesion, where healing is goodArea: fresh lesion, where healing is good

TechniquesTechniques Simple excision (excisional biopsy)Simple excision (excisional biopsy) .for simple lesions.for simple lesions Punch biopsyPunch biopsy Shave, tangential biopsyShave, tangential biopsy CurretageCurretage ElectrosurgeryElectrosurgery