Anatomy, histology, physiology of the skin. Anatomy, histology, physiology of the skin. Methods of examination of patients with skin Methods of examination of patients with skin

diseases.diseases. Morphology of primary and secondary Morphology of primary and secondary

skin lesionsskin lesions..

Lector: Shkilna M.

ContentContent

Anatomy of skin:Anatomy of skin:o EpidermisEpidermiso DermisDermiso SubcutisSubcutiso Skin appendages .Skin appendages .

Functions of the skin.Functions of the skin.Methods of examination of patients with skin diseases:Methods of examination of patients with skin diseases:o Patient’s passport.Patient’s passport.o Patient’s complaints.Patient’s complaints.o History of present illness.History of present illness.o Life history (past history).Life history (past history).o Objective investigation (Objective investigation (morphology of primary and secondary skin lesions).morphology of primary and secondary skin lesions).

Investigations.Investigations.

Anatomy of skinAnatomy of skin

EpidermisEpidermis

DermisDermis

Hypodermis or Hypodermis or subcutaneous tissuesubcutaneous tissue

Appendages (hair, Appendages (hair, nails, sebaceous and nails, sebaceous and sweat glands).sweat glands).

Epidermal LayersEpidermal Layers

DermisDermis

collagencollagen (70-80%) (70-80%) – –

for resiliency;for resiliency;

elastin elastin (1-3%) –(1-3%) –

for elasticity;for elasticity;

proteoglycansproteoglycans – –

to maintain water to maintain water within the dermis.within the dermis.

Components of the dermis:Components of the dermis:Two distinct areas:Two distinct areas:

Subcutis or subcutaneous fatSubcutis or subcutaneous fat : :

is arranged into distinct is arranged into distinct fat lobules which are fat lobules which are divided by fibrous divided by fibrous septae blood vessels, septae blood vessels, nerves, and lymphatics nerves, and lymphatics are also found in the are also found in the fibrous septae.fibrous septae.

Superficial netSuperficial net (in (in granular cell granular cell

layerlayer).).

Deep plexusDeep plexus (in subcutaneous (in subcutaneous

fat).fat).

Skin vessels:Skin vessels: Skin nerves:Skin nerves:

AppendagesAppendages

Eccrine sweat glandsEccrine sweat glands (open (open directly onto surface of skin directly onto surface of skin and regulate body temp)and regulate body temp)Apocrine glandsApocrine glands (axillae, (axillae, nipples, areolae, anogenital nipples, areolae, anogenital area, eyelids and external area, eyelids and external ears) respond to emotional ears) respond to emotional stimuli, bacteria causes body stimuli, bacteria causes body odor.odor.Sebaceous glandsSebaceous glands (secrete (secrete sebum, keep skin/hair from sebum, keep skin/hair from drying out) stimulated by drying out) stimulated by hormoneshormonesHaiHairr (Vellus and Terminal)(Vellus and Terminal)NailsNails (protect distal ends of (protect distal ends of fingers/toes)fingers/toes)

Functions of the skin:Functions of the skin:

Barrier. Barrier.

Metabolic. Metabolic.

Temperature regulation.Temperature regulation.

Secretion.Secretion.

Immune surveillance.Immune surveillance.

Coetaneous sensation.Coetaneous sensation.

Methods ofMethods of examination of patients examination of patients with skin with skin diseasesdiseases

1. Patient’s passport.1. Patient’s passport.2. Patient’s complaints:2. Patient’s complaints:a) skin rashesa) skin rashesb) subjective sensation, which are connected with b) subjective sensation, which are connected with

skin rashes: skin rashes: – itch of the skin;itch of the skin;– burning;burning;– pain;pain;– skin weeping;skin weeping;– dryness of the skin;dryness of the skin;– feeling of a tense skin;feeling of a tense skin;– weakness, weight loss, fever etc.weakness, weight loss, fever etc.

History of present illness:History of present illness:

Possible etiology of the diseasePossible etiology of the disease

( according patient’s mind).( according patient’s mind).

Duration of the disease:Duration of the disease:

Acute ( < 2 month)Acute ( < 2 month)

Chronic ( > 2 month).Chronic ( > 2 month).

Course of a disease.Course of a disease.

Previous treatment and effect from it.Previous treatment and effect from it.

Family history:Family history:

– contagious diseases;contagious diseases;

– hereditary diseases.hereditary diseases.

Life history (past history):Life history (past history):

Past medical history.Past medical history.Associated inner diseases.Associated inner diseases.Occupational hazards.Occupational hazards.Allergic history.Allergic history.Harmful habit.Harmful habit.

General state of the General state of the patient patient

( satisfactory or not, ( satisfactory or not, fever etc. ).fever etc. ).

Systems revive.Systems revive.Assessment of nails, Assessment of nails,

hair, and mucosal hair, and mucosal surfaces, even if surfaces, even if these are recorded as these are recorded as unaffected.unaffected.

Palpation Palpation ( to diagnose):( to diagnose):

Skin elastic.Skin elastic.Skin moistness.Skin moistness.Subcutaneous fat.Subcutaneous fat.Lymphatic nodes: ( size, Lymphatic nodes: ( size,

consistency, movable or consistency, movable or immovable etc.).immovable etc.).

Objective investigationObjective investigation

Inspection:Inspection:

Skin textureSkin textureLesions:Lesions:type: primary and type: primary and

secondary;secondary;color: red, brawn, white;color: red, brawn, white;shape: round, oval, shape: round, oval,

annular; annular; arrangement: grouped arrangement: grouped

(herpetiform, zoster (herpetiform, zoster form), disseminated form), disseminated (erythrodermic (erythrodermic psoriasis). psoriasis).

Configuration of Configuration of Lesions Lesions

Annular (rings)Annular (rings)GroupedGroupedLinearLinearDiffuseDiffuse

DISTRIBUTION

CONFIGURATION

Morphology of primary and Morphology of primary and secondary skin lesionssecondary skin lesions

Primary skin lesionsPrimary skin lesions

is the initial lesion that has not been altered by is the initial lesion that has not been altered by trauma, manipulation (scratching, scrubbing), trauma, manipulation (scratching, scrubbing), or natural regression over time.or natural regression over time.

Types:Types:

primary lesions without cavity;primary lesions without cavity;

primary lesions with cavity.primary lesions with cavity.

Primary lesions without cavity:Primary lesions without cavity:

Macula'sMacula's

UrticaUrtica

PapulePapule

NoduleNodule

MACULEMACULE

DescriptionDescription CircumscribedCircumscribed FlatFlat DiscolorationDiscoloration Smaller than 0.5 cm-Smaller than 0.5 cm-

maculemacule Larger that 0.5 cm- patchLarger that 0.5 cm- patch May be brown, blue, red or May be brown, blue, red or

hypo pigmentedhypo pigmented InflammatoryInflammatory NonNoninflammatoryinflammatory

TINEA VERSICOLOR

Becker's nevus. This lesion contains no pigmentation.

Becker's nevus. A typical lesion with macular pigmentation and hair.

BROWN MACULE

PAPULEPAPULE

DescriptionDescription– an elevated solid lesionan elevated solid lesion

up to 0.5 cm in diameterup to 0.5 cm in diameter

– Color varies: flesh, Color varies: flesh, yellow , white, brown, yellow , white, brown, red, blue or violetred, blue or violet

– May become confluentMay become confluent

– May form plaquesMay form plaques

PLAQUE

A circumscribed, elevated, superficial, solid lesion more than 0.5cm in diameter often formed by the confluence of papules

DescriptionDescription

PlaquePlaque

Examples of PlaquesExamples of Plaques EczemaEczema

Pityriasis roseasPityriasis roseas Tinea corporisTinea corporis

PsoriasisPsoriasis SyphilisSyphilis

PSORIASIS PLAQUE SECONDARY SYPHYLIS

NoduleNodule

DescriptionDescription– CircumscribedCircumscribed– Often roundOften round– Solid lesionSolid lesion– More that 0.5 cm in More that 0.5 cm in

diameterdiameter– Larger nodule is a Larger nodule is a

tumortumor

Metastatic carcinoma of the breast.

LIPOMA BENIGN TUMOR

WHEAL (HIVE)WHEAL (HIVE)

DescriptionDescription

Starts as red erythematous macules.Soon paleoedematous wheals develop Irregular, asymmetricalVelvety to touchErythematic well defined, fades on pressureSubside within few hours without leaving any traceDermographism positiveWheals develop along line of scratching or pressure.

Physical urticariaPhysical urticaria

Cold urticariaurticaria : Reaction to cold, such as ice, cold air or water - worse with sudden change in temperature

Primary lesions with cavity:Primary lesions with cavity:

VesiclesVesicles

BullaBulla

PustulesPustules

CystCyst

Vesicle Vesicle

DescriptionDescription

Circumscribed Circumscribed collection of free collection of free fluidfluid

Up to 0.5 cm in Up to 0.5 cm in diameterdiameter

Herpes zoster

Bulla formed dueBulla formed due to fluid in the skin and fluid to fluid in the skin and fluid collection occurs at sites where the cohesion on the skin collection occurs at sites where the cohesion on the skin

is weak:is weak:

SubcornealSubcorneal

Intra – epidermal,Intra – epidermal, due to due to individual keratinocytesindividual keratinocytes

Dermo –Dermo – epidermalepidermal junctionjunction

A circumscribed collection of free fluid more than

0,5 sm in diameter

PUSTULEPUSTULE

DescriptionDescriptionCircumscribed Circumscribed

collection of collection of leukocytesleukocytes

Free fluidFree fluidVaries in sizeVaries in size

Staphylococcal folliculitis

CYSTCYST

A circumscribed A circumscribed lesion with a wall lesion with a wall and a lumen, it and a lumen, it may contain fluid may contain fluid or solid matteror solid matter

Secondary skin lesionsSecondary skin lesions

Types:Types:

Scale.Scale.

Crusts.Crusts.

ErosionsErosions..

EROSIONEROSION

DescriptionDescription

A focal loss of epidermis;

erosions do not penetrate

below the dermoepidermal

junction; and therefore heal

without scarring Toxic epidermal necrolysis

CRUSTCRUST

DescriptionDescription

Is a collection of dried serum and cellular debris- a scabIs a collection of dried serum and cellular debris- a scab

ExamplesExamples

– Acute eczematous inflammation, Atopic on the face, Impetigo- golden Acute eczematous inflammation, Atopic on the face, Impetigo- golden or honey colored, Tinea capitis.or honey colored, Tinea capitis.

Impetigo. A thick, honey-yellow adherent crust covers the entire eroded surface.

UlcerUlcer A focal loss of A focal loss of epidermis and dermis, epidermis and dermis, and heal with scarringand heal with scarring

ExamplesExamples– DecubitusDecubitus

– IschemicIschemic

– Stasis ulcersStasis ulcers

– Neoplasm's Neoplasm's

FISSUREFISSURE

DescriptionDescriptionA linear loss of epidermis A linear loss of epidermis

and dermis with sharply and dermis with sharply defined nearly vertical defined nearly vertical wallswalls

ExamplesExamples– Chapping – hands and Chapping – hands and

feetfeet

– Eczema on the finger Eczema on the finger tiptip

Asteatotic eczema. Excessive washing produced this advanced case with cracking and fissures.

ATROPHYATROPHY

DescriptionDescription

A depression in the skin

resulting from thinning

of the epidermis or dermis

Lichen sclerosus et atrophicus. The epidermis is thin and atrophic and gives the appearance of wrinkled tissue paper when compressed.

ScarScar

DescriptionDescriptionAn abnormal formation of An abnormal formation of

connective tissue, implying connective tissue, implying dermal damage, after injurydermal damage, after injury

Are initially thick and pink, but Are initially thick and pink, but become white and atrophicbecome white and atrophic

ExamplesExamples– Post surg.Post surg.– BurnsBurns– KeloidKeloid– Post any herpesPost any herpes Keloids on the chest and extremities are

raised with a flat surface. The base is wider than the top.

EXCORIATIONEXCORIATION

An erosion caused by scratching;

excoriations are often linear.

LICHENIFICATIONLICHENIFICATION

DescriptionDescription

An area of thickened An area of thickened epidermis induced by epidermis induced by scratchingscratchingSkin lines are accentuated Skin lines are accentuated so it looks like a so it looks like a washboardwashboardExamplesExamples– Atopic dermatitis, Atopic dermatitis,

chronic eczematous chronic eczematous dermatitisdermatitis

LICHENIFICATION

ScalesScales

DescriptionDescriptionExcess dead epidermal

cells that are produced by abnormal keratinization and shedding.

The may beThe may be fine, as in pityriasis;fine, as in pityriasis;

white and silvery, as in white and silvery, as in psoriasis; psoriasis;

or large and fish-like, as or large and fish-like, as in ichthyosisin ichthyosis

Dominant ichthyosis vulgaris

INVESTIGATIONSINVESTIGATIONS

General laboratory investigationGeneral laboratory investigation::General blood analysis.General blood analysis.General urine analysis.General urine analysis.Stool test for parasites.Stool test for parasites.Examination of blood for sugar.Examination of blood for sugar.Wasserman reaction.Wasserman reaction.

INVESTIGATIONSINVESTIGATIONS

Diagnostic TestsDiagnostic TestsSkin Biopsy Skin Biopsy Culture and sensitivity (viral, bacteria, fungi)Culture and sensitivity (viral, bacteria, fungi)ImmunofluorescenceImmunofluorescenceAllergy TestsAllergy Tests Skin ScrapingsSkin ScrapingsTzanck SmearTzanck SmearWood’s Light ExaminationWood’s Light ExaminationClinical PhotographsClinical PhotographsDiascopyDiascopy

EPILUMINESCENCE MICROSCOPY EPILUMINESCENCE MICROSCOPY (DERMATOSCOPY, DERMOSCOPY) (DERMATOSCOPY, DERMOSCOPY)

This refers to surface This refers to surface microscopy using an microscopy using an illuminated lens with oil illuminated lens with oil immersion directly on to the immersion directly on to the skin's surface. The presence skin's surface. The presence of oil reduces specular of oil reduces specular reflection and reduces reflection and reduces 'errors' due to the different 'errors' due to the different refractive indexes of the refractive indexes of the various superficial layers of various superficial layers of skinskin. .

SCRAPINGSCRAPING

Hidden scaling of the Hidden scaling of the skin.skin.

Psoriatic phenomenonts.Psoriatic phenomenonts. Purpura symptom.Purpura symptom.

Step A: Gently scrape the lesion with a glass slide. This

accentuates the silvery scales (Grattage test positive).

Scrape off all the scales.Step B: As you continue to scrape the lesion, a

glisteningwhite, adherent membrane appears.

Step C: On removing the membrane, punctate bleeding

points become visible.

DIASCOPYDIASCOPY

A glass slide is pressed firmly on A glass slide is pressed firmly on the skin lesion. If a red lesion the skin lesion. If a red lesion blanches, it implies that the red blanches, it implies that the red colour is secondary to blood within colour is secondary to blood within the vessels. By contrast, blood the vessels. By contrast, blood outside the vessels, such as that outside the vessels, such as that from a bruise or from vasculitis, from a bruise or from vasculitis, will not blanch. will not blanch.

Success in blanching is a more Success in blanching is a more useful physical sign than failure to useful physical sign than failure to blanch. blanch.

Granulomatous lesions a glass slide Granulomatous lesions a glass slide reveals an appearance commonly reveals an appearance commonly referred to as 'apple jelly nodule'. referred to as 'apple jelly nodule'.

Inflammatory or Inflammatory or

no inflammatory types of no inflammatory types of lesionslesions

WOOD'S LIGHTWOOD'S LIGHT

This involves irradiation with a UV light This involves irradiation with a UV light source that causes normal skin, particularly source that causes normal skin, particularly dermis, to fluoresce (in the visible light dermis, to fluoresce (in the visible light range). range).

The basis for this is that in the ultraviolet The basis for this is that in the ultraviolet A wavebands used by Wood's light, A wavebands used by Wood's light, pigmentation has a greater degree of pigmentation has a greater degree of absorption than at longer wavebands, absorption than at longer wavebands, resulting in a greater degree of difference resulting in a greater degree of difference in fluorescence between pigmented and in fluorescence between pigmented and depigmented skin. depigmented skin.

Wood's light also enhances the Wood's light also enhances the examination of cutaneous pigmentary examination of cutaneous pigmentary abnormalities such as in patients with abnormalities such as in patients with vitiligo, where areas of subtle vitiligo, where areas of subtle

depigmentation are more easily seen.depigmentation are more easily seen.

MYCOLOGY SAMPLESMYCOLOGY SAMPLES

Coetaneous scale, nail clippings and plucked hairs can be Coetaneous scale, nail clippings and plucked hairs can be examined by light microscopy when mounted in 20% examined by light microscopy when mounted in 20% potassium hydroxide. potassium hydroxide.

The keratin is dissolved, allowing fungal hyphae to be The keratin is dissolved, allowing fungal hyphae to be identified.identified.

SWABSSWABS

Bacterial swabs in an appropriate culture medium are sometimes Bacterial swabs in an appropriate culture medium are sometimes useful. useful.

PRICK TESTSPRICK TESTS

Prick tests are a way of detecting coetaneous type I (immediate)Prick tests are a way of detecting coetaneous type I (immediate) hypersensitivity to various antigens such as pollen, house dust mite or dander.hypersensitivity to various antigens such as pollen, house dust mite or dander. The skin is pricked with a dilution of the appropriate antigen solution. AfterThe skin is pricked with a dilution of the appropriate antigen solution. After 10 minutes a positive response is indicated by a weal and a flare. The weal is 10 minutes a positive response is indicated by a weal and a flare. The weal is due to a local increase in capillary permeability and the flare a result of due to a local increase in capillary permeability and the flare a result of

activation of the axon reflex. activation of the axon reflex.

IMMUNOFLUORESCENCEIMMUNOFLUORESCENCE

A portion of the skin biopsy can be frozen in liquid A portion of the skin biopsy can be frozen in liquid nitrogen for direct immunofluorescence (IF). This nitrogen for direct immunofluorescence (IF). This involves visualising antigens that are present in skin involves visualising antigens that are present in skin by identifying them with fluorescein-labelled by identifying them with fluorescein-labelled antibodies. Similarly, indirect immunofluorescence antibodies. Similarly, indirect immunofluorescence can identify circulating antibodies in the serum by an can identify circulating antibodies in the serum by an additional step of adding the serum to a section of additional step of adding the serum to a section of normal skin or other substrate. Immunofluorescence normal skin or other substrate. Immunofluorescence plays a major role in the diagnosis of the autoimmune plays a major role in the diagnosis of the autoimmune bullous disorders.bullous disorders.

ELECTRON MICROSCOPYELECTRON MICROSCOPY

This investigation has played an important role in the This investigation has played an important role in the diagnosis of some of the rare blistering disorders such as diagnosis of some of the rare blistering disorders such as epidermolysis bullosa, although the availability of a range epidermolysis bullosa, although the availability of a range of antibodies to basement membrane zone antigens has in of antibodies to basement membrane zone antigens has in part replaced it.part replaced it.

PHOTOTESTINGPHOTOTESTING

Phototesting involves exposing skin (often on the back) to a Phototesting involves exposing skin (often on the back) to a graded series of doses of ultraviolet radiation (UVR) of graded series of doses of ultraviolet radiation (UVR) of known wavelength, either on one occasion or repeatedly.known wavelength, either on one occasion or repeatedly.

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