MORPHOLOGY MORPHOLOGY OF OF

SKIN LESIONSSKIN LESIONS

Dr. Riaz Uddin AhmedDr. Riaz Uddin AhmedMBBS, DDV, MCPS, FCPSMBBS, DDV, MCPS, FCPS

Associate Professor of Associate Professor of DermatologyDermatology

Bangladesh Medical CollegeBangladesh Medical College

A. Primary lesions-A. Primary lesions- The original lesions The original lesions are known as primary lesion which are are known as primary lesion which are as follows:as follows: Macule, patchMacule, patch Papule, plaque, nodule, tumorPapule, plaque, nodule, tumor Wheals Wheals VesicleVesicle BullaeBullae PustulePustule

B. Secondary Lesions:B. Secondary Lesions: the primary lesions the primary lesions continue to full development or may be continue to full development or may be modified by regression, trauma of other modified by regression, trauma of other extraneous factors, producing secondary extraneous factors, producing secondary lesion which are as follows:lesion which are as follows:

ScalesScales CrustsCrusts Excoriations and abrasionsExcoriations and abrasions FissuresFissures ErosionsErosions UlcersUlcers Scar-hypertrophic scarsScar-hypertrophic scars KeloidKeloid AtrophyAtrophy CystCyst

C. Special Lesion:C. Special Lesion: lesions that are lesions that are produced special circumstances of produced special circumstances of body system which are as follows:body system which are as follows:

Erythema-Erythema multiforme, erythema Erythema-Erythema multiforme, erythema nodosumnodosum

TelangiectasiaTelangiectasia PurpuraPurpura PetechiaePetechiae EcchymosesEcchymoses VibicesVibices HaematomaHaematoma Erythroderma (exfoliative dermatitis)Erythroderma (exfoliative dermatitis)

A. Primary LesionsA. Primary Lesions

Mucule- Latin: Mucule- Latin: macula, “spot”macula, “spot”

Macules are Macules are variously variously sized, sized, circumscribecircumscribed changes in d changes in skin color, skin color, without without elevation or elevation or depression depression and less than and less than 1 cm in 1 cm in diameterdiameter

Macule

Papule

Patch: A patch is a circumscribed Patch: A patch is a circumscribed changes in skin color without changes in skin color without elevation or depression and 1 cm or elevation or depression and 1 cm or greater in diametergreater in diameter

Papule- (Latin Paula, “Pimple”)Papule- (Latin Paula, “Pimple”)

Papules are circumscribed, solid Papules are circumscribed, solid elevations of skin having diameter elevations of skin having diameter less than 1 cmless than 1 cm

Plaques: (French- Plaques: (French- Plaque- “Plate”)Plaque- “Plate”)

A plaque is a broad A plaque is a broad papule (or papule (or confluences of confluences of papules), 1 cm or papules), 1 cm or more in diameter.more in diameter.

Nodule

Plaque

Crust

Vesicle

Pustule

Wheal

Scale

Erosion

Erythroderma

Hypertrophic Scar

Keloid

Purpura

Nodules (Latins: nodulus- “small Nodules (Latins: nodulus- “small knot”)- Nodules are form of papules knot”)- Nodules are form of papules but largest (>1 cm) and invade but largest (>1 cm) and invade deeply.deeply.

TumorsTumorsTumors are soft or firm and freely movable or fixed Tumors are soft or firm and freely movable or fixed masses of various sizes and shape. “A tumor is an masses of various sizes and shape. “A tumor is an abnormal mass of tissue, the growth of which abnormal mass of tissue, the growth of which exceeds and un-coordinated with normal tissue and exceeds and un-coordinated with normal tissue and persists in the same excessive manner after cessation persists in the same excessive manner after cessation of stimulus which evoked the change”.of stimulus which evoked the change”.

Wheals (Hives) wheals are evanescent, oedematous, Wheals (Hives) wheals are evanescent, oedematous, flat elevations of various sizes.flat elevations of various sizes.

Vesicles (Latin “Little bladder”) vesicles are Vesicles (Latin “Little bladder”) vesicles are circumscribed epidermal elevations 1-10 mm in size circumscribed epidermal elevations 1-10 mm in size and usually containing clear fluid.and usually containing clear fluid.

Bulloe (Latin-”Bubble”)- Bulloe are circumscribed or Bulloe (Latin-”Bubble”)- Bulloe are circumscribed or irregularly shaped cavity more than 10 mm in irregularly shaped cavity more than 10 mm in diameter containing serous or seropurulent fluid.diameter containing serous or seropurulent fluid.

Pusteules (Latin- Pustula-Pus)- pustules are small Pusteules (Latin- Pustula-Pus)- pustules are small elevations of the skin containing puselevations of the skin containing pus

Secondary LesionsSecondary LesionsScalesScales:: (Latin Squama-scales)- scales are dry or greasy laminated (Latin Squama-scales)- scales are dry or greasy laminated masses of keratin.masses of keratin.

ExcoriationsExcoriations (Latin Abrasio)- an excoriation is a punctate or linear (Latin Abrasio)- an excoriation is a punctate or linear abrasion produced by mechanical means usually involving only the abrasion produced by mechanical means usually involving only the epidermis and rarely reaching the papillary layer of the dermis.epidermis and rarely reaching the papillary layer of the dermis.

FissuresFissures (Latin- Cracks)- a fissure is a linear cleft through the (Latin- Cracks)- a fissure is a linear cleft through the epidermis or rarely into the dermis caused by disease or injuryepidermis or rarely into the dermis caused by disease or injury

ErosionsErosions – loss of all or portion of epidermis alone – loss of all or portion of epidermis alone

UlcersUlcers (Latin- Ulcus- “Sore”)- ulcers are rounded or irregularly shaped (Latin- Ulcus- “Sore”)- ulcers are rounded or irregularly shaped excavations that result from loss of epidermis and dermis.excavations that result from loss of epidermis and dermis.

CrustsCrusts (Latin- crusta-bark)- crusts are dried serum, pus or blood, (Latin- crusta-bark)- crusts are dried serum, pus or blood, usually mixed with epithalial and bacterial debris.usually mixed with epithalial and bacterial debris.

ScarsScars ( )- scars are new formations in the dermis or deeper parts as a ( )- scars are new formations in the dermis or deeper parts as a result of injury or disease, as a part of the normal reparative and result of injury or disease, as a part of the normal reparative and healing process scar may be hypertrophic.healing process scar may be hypertrophic.

KeloidKeloid (Latin- Cheloid-clawlike)- a keloid is a firm, irregularly shaped, (Latin- Cheloid-clawlike)- a keloid is a firm, irregularly shaped, thickened, hypertrophic, fibrous, pink or red excrescence.thickened, hypertrophic, fibrous, pink or red excrescence.

Hypertropic ScarHypertropic Scar KeloidKeloid

Claw-like prejections Claw-like prejections absentabsent

There is claw-like There is claw-like projections present projections present in Keloid in Keloid

Hypertrophic scar Hypertrophic scar does not extend does not extend beyond the original beyond the original woundwound

Keloid extend and Keloid extend and spread beyond the spread beyond the limits of the original limits of the original injury injury

In hypertrophic scar, In hypertrophic scar, there is sponteneous there is sponteneous improvement within improvement within first six monthsfirst six months

Sponteneous Sponteneous improvement does improvement does not occur in Keloidnot occur in Keloid

Ulcer

Scar

Atrophy

Atrophy:Atrophy: this refers to this refers to a diminuation of a diminuation of some or all layers of some or all layers of kinkin

Cyst:Cyst: a cyst is a a cyst is a cavity containing cavity containing liquid or solid or liquid or solid or semi-solid material semi-solid material may be superficial may be superficial or deep.or deep.

Cyst

SPECIAL LESIONSSPECIAL LESIONS

Erythema: erythema may be defined as Erythema: erythema may be defined as redness of skin due to dilatation of blood redness of skin due to dilatation of blood vassals which may be localised or wide spread vassals which may be localised or wide spread near the surface of the skin.near the surface of the skin.

Erythema multiforme:Erythema multiforme: erythema multiforme is erythema multiforme is a mucocuteneous in which various types of a mucocuteneous in which various types of skin reaction may occur from the same skin reaction may occur from the same causative agents and conversely many causative agents and conversely many causative agents may induce same cutaneous causative agents may induce same cutaneous and mucous membrane reactions.and mucous membrane reactions.

Erythema nodosum:Erythema nodosum: erythema nodosum is an erythema nodosum is an inflammatory but non-suppurative condition of inflammatory but non-suppurative condition of the skin characterized by erythematous, the skin characterized by erythematous, tender nodules, usually located over extensor tender nodules, usually located over extensor aspects of lower limbs.aspects of lower limbs.

Erythroderma:Erythroderma: erythroderma isa terminal erythroderma isa terminal condition of any inflammatory disorder which condition of any inflammatory disorder which affects either universally or more than 90% affects either universally or more than 90% body surface area characterised by erythema, body surface area characterised by erythema, oedema, scaling, thickening and itching oedema, scaling, thickening and itching chilliness caused by idiopathic, drug or chilliness caused by idiopathic, drug or secondary to some reactional process to an secondary to some reactional process to an underlying systemic or cutaneous dermatosis.underlying systemic or cutaneous dermatosis.

Telengiactasia:Telengiactasia: permanent dilatation of blood permanent dilatation of blood vassals is known as Telengietasia.vassals is known as Telengietasia.

Purpura:Purpura: purpura may be defined as bleeding purpura may be defined as bleeding in the skin and mucous membrane from the in the skin and mucous membrane from the capillary at the arterio-capillary junction capillary at the arterio-capillary junction which does not blanch on pressure and has which does not blanch on pressure and has progressive colour change.progressive colour change.

PetechiaePetechiae- are superficial, pinhead sized (less - are superficial, pinhead sized (less than 3 mm), round, haemorrhagic macules, than 3 mm), round, haemorrhagic macules, bright red at first then brwonwish or rust bright red at first then brwonwish or rust coloured.coloured.

Ecchymoses:Ecchymoses: siguify a deeper and extensive siguify a deeper and extensive inter stitial haemorrhage, which forms a flat inter stitial haemorrhage, which forms a flat irregularly shaped, bluists-purplish patch.irregularly shaped, bluists-purplish patch.

VibicesVibices (singuler-vibex) are linear purpuric (singuler-vibex) are linear purpuric lesions.lesions.

Haematoma:Haematoma: designates a pool-like collection designates a pool-like collection of extravasated blood in a dead space in of extravasated blood in a dead space in tissue that, if of sufficient size, produces tissue that, if of sufficient size, produces swelling that fluctuates on palpation.swelling that fluctuates on palpation.