Lesions Of Skin

Dr.Gurjot Singh Marwah JUNIOR RESIDENT

(Dept. of Dermatology) M.G.M Hospital, Aurangabad

Types Of Lesions

Primary Lesions

Secondary Lesions

Tertiary Lesions

Primary Lesions

Definition : lesion occurring on non pathological skin which have not been altered by trauma, manipulation (scratching, scrubbing), or natural regression over time.

Examples• Macule• Papule• Patch ???• Plaque• Nodule• Wheal• Vesicle• Bulla• Pustule• Cyst

Macule

• Definition : Flat, circumscribed skin discoloration that lacks surface elevation or depression, less than 1 cm in diameter*

• TYPES1)Hypopigmented : due to decrease in number of melanocytes or the amount of pigment they produce E.g. : tuberous sclerosis , nevus achromicus , etc nevus achromicus

2)Depigmented : due to complete loss of melanocytesE.g.: vitiligo , halonaevus

3)Hyperpigmented : due to excess of melanin in skin

A)brown or black : due to excess of melanin in epidermisE.g.: freckles or chloasma

B)Bluish-grey : due to increase melanin in dermis ( tyndall effect ) E.g : Mongolian spot, nevus of Ota

C)Erythema: increased blood flow through the skin causing capillary dilatationE.g : macular viral and drug rash

D)Purpura/Ecchymosis: extravasation of RBCs in Dermis(large purpura : ecchymosis)E.g : thrombocytic purpura Schamberg’s purpura

Solid , well circumscribed elevated lesion, less than one cm in diameter

Formed by1)hyperplasia of epidermis , dermis or bothE.g : verruca vulgaris2)Metabolic deposits or cellular infiltrates E.g : xanthelasma

SHAPE

COLOUR

Shape• Pointed : Follicular Lichen planus• Papulosquamous : Guttate Psoriasis• Dome : Molluscum contagiosum• Flat topped : lichen plannus

Colour

• Red : Psoriasis• Pearly white : molluscum contagiosum• Violaceous : Lichen planus• Coppery : seccondary syphilis• Yellowish : Xanthelasma• Blue/Black : Mallignant Melanoma• Purpuric : henoch-schönlein purpura

Plaque

•Elevated well circumscribed more than 1 cm in diameter ,occupying relatively large surface area in comparison with its height above the skin surface

TypesScaly Plaque : Psoriasis , P.Rosea

• Lichenified plaque : Lichen Simplex Chronicus

• Erythematous plaque : Tuberculoid leprosy

Patch• Patch / Large macule ???

Nodule• Palpable solid round lesion ,usually larger than

1cm in diameter .occupying relatively larger vertical diameter as compared to suface diameter.

• PAPULE NODULE • SEEN BETTER FELT BETTER

• E.g : erythema nodosum,Lipoma,Sebaceous cyst kerato acanthoma,xanthelasma,

Wheals• Evanescent , edematous , platue-like

elevations of various sizes • Usually oval or arcuate , pink to red ,

surrounded by a flare of macular erythema• Caused by transient vascular reaction in the

upper dermis mainly due to vasodilatation and increased permeability of capillaries

• It is the characteristic lesion of urticaria

Wheals

Vesicle AND Bullae• Elevated ,superficial well circumscribed lesion containing clear

fluid , less than 0.5 cm in diameter

• A vesicle larger than 0.5 cm is known as Bullae• They can arise by separation of skin at different levels i.e a) interepidermal eg bullous impetigo b) supra basal e.g Pemphigus vulgaris c) dermoepidermal eg erythema multiforme

• Lesions may be • A) tense : Pompholyx

• Flaccid : Pemphigus Vulgaris

• Umblicated : varicella zoster

Pustule

• Well-circumscribed, elevated lesion containing visible purulent exudate

• Pustules are characteristic of pustular psoriasis, pyoderma, rosacea

Cyst

• A sac that contains liquid or semisolid material in a well-defined cavity

• 2 most common type-• A) Epidermal cyst: lined with squamous

epithelium and produce keratinous material• B) pilar cyst: originate from hair follicle lined

with multilayered epithelium

Abscess• An abscess is a collection of pus below the

skin

• Pus in an abscess is invisible but clinically be interpreted as sign of inflammation in the overlying skin

• • Abscess cavities do not have well-defined

lining as cyst

Secondary lesions: modification of primary skin lesions that result from traumatic injury , evolution from

primary lesion , or other external factors

• Crust• Scale• Erosion• Ulcer• Fissure• Scar• Atrophy• Telangiectasia

Crust• A collection of cellular

debris ,dried serum,pus or blood and sometimes bacterial debries

• antecedent primary lesion is usually a vesicle,bulla or pustule

Types• Golden yellow,soft friable : Impetigo

• Yellowish : Flavus

• Thick hard and tough : third degree burns

• Lamillated,elevated, black or green : syphillus (oyster shell)

Erosion

• Partial focal loss of the epidermis alone. Heals without a scar

• Eg herpes zooster, TEN,Erosion interdigitale

Scale• Abnormal shedding or accumulation of the

stratum corneum in visible flakes is called scaling• Formed due to - a) formation of epidermal cells is rapid OR b) process of normal keratinisation is interferred with

Types• Fine and delicate : P.versicolor

• Coarse : eczema

• Stratified : Psoriasis

Ulcer

• A full-thickness, focal loss of epidermis along with parts of dermis ,heals with scarring

• E.g : bed sores , Syphillus Diabetic foot

Fissure• Linear cleft in the skin through the epidermis and part of dermis may be single or multiple ranging from microscopic to a few millimeters having well defined margins They occur most commonly when skin is dry and thickened due to inflamation

Pain is often produced by movement of part,Which opens or deepens the fissure

Commonest sites a) tips and flexural creases of thumb , finger and palms b) edges of heel c)clefts between fingers and toess d) angle of mouth,the lips,nares auricles and anus

Scar• A collection of new connective tissue, that

replaces lost substances in the demis or deep dermal tissues

• They may be atrophic or hypertrophic

• Hypertrophic scars / Keloid develop when fibrous components predominate

Excoriation And AbrasionPunctate or linear abrasion produced by mechanical meansUsually involving only the epidermis Caused by scratching with fingernails in a variety of diseaseE.g : atopic dermatitis , Scabies

If the damage is due to constant friction or mechanical trauma the word Abrasion may be used

AtrophyReduction in the components of a tissue,Organ or part of bodyIn skin1) Epidermal Atrophy results from decrease in

epidermal cells .Gives rise to frequently transparent epidermis and alteration of skin surface i.e(loss of normal skin lines and fine wrinkling

2) Dermal Atrophy results from decrease in the reticular or papillary dermis .Clinically seen as depression of skin

• Usually dermal and epidermal atrophy seen together E.g : D.L.E,Lichen sclerosus et atrophicus

3)Atrophy of paniculus caused due to lipoatrophy.Clinically seen as deep depression

Lichenification

• Focal area of thickened skin produced by chronic scratching or rubbing

• Clinically triad of accentuation of skin markings ,thickening of epidermis and Hyperpigmentation

• Eg : lichen Simplex Chronicus usually seen superimposed on pruritic conditions

Telangiectasia

• Small, dilated ,superficial blood vessels that disappear with pressure

• E.g : Scleroderma , Rosacea

Special Lesions• Lesions that are pathognomic to certain skin

conditions

COMEDO:Non inflamatory lesions of acne resulting from impaction of pilosebaceous gland

• OPEN COMEDO• Impaction occurs in

dilated follicular orifice• Visible as black

keratinous mass i.e. blackhead

• Closed Comedo• Impaction occurs lower

down in follicular orifice• They are not dilated • Lesions appear slightly

lighter than skin colour i.e. whitehead

Target lesions

• Pathognomic to erythema multiformeThree zones1) central, dark sometimes blistered 2)surrounded by,pale edematous zone 3)rimmed by, zone of erythema

Milia• Milia are small superficial

cyst with an epidermal lining

• Commonly seen in neonates• Especially in periorbital

areas

Burrow

Serpinginous tunnel in the skin made by scabies mite.About 5mm in length

Scabies