1.-Introduction-to-the-genral-deramtology

SKIN LESIONS

Zharlah Gulmatico-Flores, M.D., FPDS,FPADSFI, FAAD

College of Medicine

Credits to Dr. Roberto Manlapig, MD, FPDS

PRIMARY

SKIN LESIONS

MACULE

MACULE

● circumscribed area of change in

normal skin color

● no elevation or depression of

surrounding skin

● measures less than 10 mm

● lesion measuring more than

10 mm is known as a patch

MACULE

● shape may be circular, oval, or irregular

● outline may be distinct, or fade into

the surrounding area

MACULE

● pigmentary changes

- hyperpigmentation

MACULE


- hypopigmentation

MACULE

● permanent vascular

abnormalities of the skin

MACULE

● transient capillary dilatation

PATCH

PATCH

● large macule

● 1 cm or greater in diameter

PATCH


- hyperpigmentation

PATCH


- hypopigmentation

PATCH

● permanent vascular

abnormalities of the skin

PAPULE

PAPULE

● circumscribed solid elevation

with no visible fluid

● generally smaller than

0.5 cm. in diameter

PAPULE

● major portion of the papule projects

above the skin surface

PAPULE

● may be soft or firm in consistency

PAPULE

● surface may be smooth or rough

PAPULE

● may be located

- dermis

- around sebaceous glands

- orifices of sweat ducts

- hair follicles

PAPULE

PAPULE

● elevation is caused by:

- metabolic deposits in the dermis

- localized infiltrates in the dermis

- localized hyperplasia of cellular

elements in the dermis

PAPULES

PLAQUE

PLAQUE

● an elevation above the skin surface

occupying a relatively large surface area

PLAQUE

● generally flat

● measures 1 cm. or more in diameter

PLAQUE

● frequently formed by confluence of

papules

NODULE

NODULE

● palpable, solid ,round or ellipsoidal lesion

● deeper than a papule

NODULE

● located at:

! dermis

! subcutaneous tissue

NODULE

● Depth of involvement and palpability,

. differentiates a nodule from a papule.

NODULE

● generally persistent

● often indicate systemic disease

● result from:

- infiltrates

- neoplasms

- metabolic deposits

TUMOR

TUMOR

● soft or firm, fixed or freely movable

mass

● vary in size and shape

● sessile or pedunculated

TUMOR

● lesions:

- remain stationary indefinitely

- increase in size

- break down due to necrosis

or infection

TUMOR

● lesions:

-remain stationary indefinitely

TUMOR

● lesions:

- increase in size

TUMOR

● lesions:


or infection

TUMOR

● lesions:


or infection

WHEAL

WHEAL

● rounded or flat-topped, pale red

papule or plaque

● may be discrete or coalesce to form

solid plaques

WHEAL

● may be round, gyrate, or irregularly

shaped with pseudopods

WHEAL

● changes rapidly in size and shape

-due to shifting edema in the dermis

WHEAL

● evanescent, disappearing within hours

WHEAL

● dermographism may be evident

● pruritus is always present

VESICLE

VESICLE

● Circumscribed epidermal elevated

lesion containing fluid

● 1-10 mm in diameter

VESICLE

● thin walls translucent

-serum, lymph fluid, blood or

extra-cellular fluid can be seen

VESICLE

● occasionally have reddish areola

VESICLES

VESICLE

BULLA

BULLA

● round or irregularly shaped blister

containing serous or seropurulent

discharge

● large vesicle, more than 1 cm.

BULLA

● round or irregularly shaped blister

containing serous or seropurulent

discharge

● large vesicle, more than 1 cm.

BULLA

● may be located superficially in the

epidermis

● rupture

- remnants of the thin walls and

exudate form crust

BULLA


epidermis

● rupture

- raw and moist base covered by

seropurulent or purulent slough

BULLA


epidermis

BULLA

PUSTULE

PUSTULE

● a circumscribed elevation of the skin

that contains a purulent exudate that

may be white, yellow, or greenish yellow

PUSTULE

● may be reddish if they contain blood,

together with pus

PUSTULE

● usually has an inflammatory areola

● vary in size and shape

● vesicular lesions may become pustular

PUSTULES

SECONADRY

SKIN LESIONS

FISSURES

FISSURES

● linear clefts through the epidermis,

rarely into the dermis

● caused by disease or injury

● single or multiple

FISSURES

● vary from tiny cracks to clefts of

several centimeters in length

● dry or moist

● straight, curved, irregular or branching

FISSURES

● occur most commonly when the skin is

thickened and inelastic due to

inflammation and dryness

FISSURES

● commonly seen in regions subjected to

frequent movement

● movement often accompanied by pain

- deepening of cracks

- formation of new cracks

FISSURES

CRUSTS

CRUSTS

● dried serum, pus, or blood

● usually mixed with epithelial and

bacterial debris

CRUSTS

● vary greatly in size, thickness, shape,

and color according to origin,

composition, and amount of discharge

- yellow (dried serum)

CRUSTS




- green or yellow-green (purulent)

CRUSTS




- brown or dark red (blood)

CRUSTS

● may be thin, delicate, and friable

or thick and adherent

CRUSTS

● when thin crusts become detached

-base may be dry or red and moist

-usually heals without scarring

CRUSTS

EROSIONS

EROSIONS

● loss of all or portions or the epidermis

● may or may not become crusted

● heals without scarring

ULCER

ULCER

● rounded or irregularly shaped excavations

● results from loss of dermis and epidermis

● few millimeters to several centimeters

ULCER

● may be shallow, involving only beyond

the epidermis, or may extend deep

into the dermis

ULCER

● heals with scarring

ULCER

● Features helpful in determining cause:

- location

- borders

- base

- discharge

- associated topographic

features

ULCER

● Associated topographic features

- nodules, excoriations,

varicosities

- hair distribution

- sweating

- pulses

ULCER

ULCER

SCARS

● new formations of connective tissue in the

dermis or deeper as a result of injury or

disease

● part of normal reparative and healing process

● size and shape determined by previous

destruction

● persistent, less noticeable in time

● may grow thick, tough, and corded

SCARS

SCALES

SCALES

● dry or greasy laminated masses of keratin

● vary is size

-fine, delicate and branny (P.versicolor)

SCALES

● vary is size

-coarse (ichthyosis)

SCALES

● vary is size

- stratified (psoriasis)

SCALES

● vary is size

- sheets (exfoliative dermatitis)

SCALES

● may be thin, dry, brittle shiny flakes

SCALES

● may be dull and greasy

SCALES

Structures of the Skin

Basic Layers of the Skin

• Epidermis

• Dermis

• Subcutaneous

Tissue

DERMIS

DERMIS

DERMIS

DERMIS

• constituents are

mesodermal origin

except:

nerves

– from neural crest

melanocytes (?)

DERMIS

EMBRYOGENESIS

• 6 th weeks

• merely a pool of acid-mucopoly-saccharidecontaining,

scattered dendritic-shaped cells

• precursors of fibroblasts

DERMIS

EMBRYOGENESIS

• 12 th week

• fibroblasts actively synthesizing

reticular fibers

elastic fibers

collagen

• vascular network develops

• 24 th weeks

• fat cells appear beneath the dermis

Components of the Dermis

COLLAGEN

• principal component of the dermis

• family of fibrous proteins comprising at least

15 genetically distinct types in human skin

• serves as the major structural protein

for the entire body

• found in tendons, ligaments, lining of bones

• dermis of the skin

• 70% of the dry weight of skin


• rich in the amino acids:

hydroxyproline

hydroxylysine

glycine

COLLAGEN

• fibrillar collagens are the major group found in the

skin

• Type I collagen is the major component

dermis

of the


COLLAGEN

• Type I collagen

uniform in width

each fiber displays characteristic

cross striations with a periodicity of

68 nm


COLLAGEN

• Type IV collagen

found in the BMZ

• Type VII collagen

major structural component of

anchoring fibrils

produced predominately by

keratinocytes


COLLAGEN

• loosely arranged in the

papillary and adventitial

(periadnexal) dermis

• large bundles are noted

in the reticular dermis


COLLAGEN

• tightly packed in a fascicle-like pattern within

the reticular (lower) portion of the dermis

• continously being degraded by proteolytic

enzymes called collagenase

• continously replaced by newly synthesized

fibers


COLLAGEN

• tightly packed in a

fascicle-like pattern

within the reticular

(lower) portion of the

dermis


COLLAGEN

• continously being degraded by proteolytic

enzymes called collagenase

• continously replaced by newly

synthesized fibers


RETICULAR FIBERS

• also synthesized from

fibroblasts

• similar to collagen in their

periodicity although smaller

in diameter

• large numbers are found

within the upper part of the

papillary dermis


ELASTIC FIBERS

• differ both structurally and

chemically from collagen

• consists of aggregates of:

protein filaments

elastin

• serve as anchoring fibrils

for the basal lamina


ELASTIC FIBERS

• with amino acids unique to

elastic fibers

desmosine

isodesmosine

• fine in papillary dermis

• coarse in reticular dermis


GROUND SUBSTANCE

• extracellular matrix

• composed of:

glycosaminoglycans or

sulfated acid mucopolysacharide

hyaluronic acid

chondroitin sulfate

dermatan sulfate

neutral musopolysaccharide


GROUND SUBSTANCE

• Hyaluronan (hyaluronic acid)

minor component of normal dermis

major mucopolysaccharide that

accumulates in pathologic states


VASCULATURE

• course within the papillary

portion of the dermis

parallel to the epidermis

• furnishes a rich supply of

capillaries, end anterioles,

and venules to the dermal

papillae


VASCULATURE

• dermal vasculature consists principally of two

important intercommunicating plexuses:

subpapillary plexus or

upper horizontal plexus

deep plexus or

lower horizontal plexus


VASCULATURE

■ SUBPAPILLARY PLEXUS OR

UPPER HORIZONTAL PLEXUS

• contains the post-capillary venules

• courses at the junction of the

papillary and reticular dermis

• furnishes a rich supply of capillaries,

end arterioles, and venules to the

dermal papillae


VASCULATURE

■ DEEP PLEXUS OR

LOWER HORIZONTAL PLXUS

• located at the dermal-subcutaneous

interface

• composed of larger blood vessels than

those of the superficial plexus

• found around hair follicles and eccrine

glands


MUSCLES

■ STRIATED MUSCLE

• skin of the face (muscles of facial expression)


MUSCLES

■ STRIATED MUSCLE

• skin of the neck (platysma)


MUSCLES

■ SMOOTH MUSCLE

• occurs in the skin as:

arrectores pilorum

(erectors of the hair)

tunica dartos

(dartos of the scrotum)

in areolas around the nipples

anogenogenital skin


MUSCLES

■ SMOOTH MUSCLE


arrectores pilorum

(erectors of the hair)

tunica dartos

(dartos of the scrotum)


anogenogenital skin


MUSCLES

■ SMOOTH MUSCLE




MUSCLES

■ SMOOTH MUSCLE


tunica dartos (dartos of the scrotum)


MUSCLES

■ SMOOTH MUSCLE


arrectores pilorum (erectors of the hair)


MUSCLES

■ SMOOTH MUSCLE

• also comprises the muscularis of dermal

and subcutaneous blood vessels

muscularis of veins composed of small

bundles of smooth muscle that

criss-cross at right angles


MUSCLES

■ SMOOTH MUSCLE

• also comprises the muscularis of dermal

and subcutaneous blood vessels

arterial smooth muscle forms a

concentric wreath-like ring


MUSCLES

■ SMOOTH MUSCLE

• glomus bodies

specialized aggregates of smooth muscle

cells found between arterioles

and venules

best developed on the digits


MUSCLES

■ SMOOTH MUSCLE

• glomus bodies

serves to slunt blood from the arterial to

the venous side of the capillaries where

exchange of oxygen and heat takes place


NERVES

• dermis rich in nerves

• travel in the deep dermis

parallel to the surface

• nerve bundles are found

together with arterioles

and venules as part of

the neurovascular bundle


NERVES

■ MEISSNER’S CORPUSCLES

• found in the dermal papillae,

particularly on digits, palms and soles

• mediates touch and pressure sensation


NERVES

■ VATER-PACINI CORPUSCLES

• located in the deeper portion of the dermis

of weight-bearing surfaces and genitalia


NERVES

■ MUCOCUTANEOUS END ORGANS

• found in papillary dermis of the modified

hairless skin at the mucocutaneous junction

glans

prepuce

clitoris

labia minora

perianal region

vermillion border of lips


NERVES

■ UNMYELINATED NERVE FIBERS

• terminate in the papillary dermis

and around hair follicles

• mediates sensation of

temperature

pain

itch


NERVES

• impulse

pass to the central nervous system by

way of the dorsal root ganglia


NERVES

■ POST GANGLIONIC FIBERS OF ANS

• regulate

vasoconstruction

apocrine gland secretion

contraction of arrector pili muscles


NERVES

■ CHOLINERGIC FIBERS

• mediate

eccrine sweat secretion


MAST CELL

• important constituent of the dermis

• 6-12 microns in diameter

• with ample amphophoteric cytoplasm

and a small round central nucleus

• normal mast cells resemble fried eggs in

histologic sections


MAST CELL

• contains up to 1000 granules

• with 100,000 to 500,0000 glycoprotein

receptor sites for Ig E on the cells surface


MAST CELL

■ GRANULES

• stain metachromatically due to their

high content of heparin

• also contain:

histamine

neutrophil chemotactic factor

eosinophil chemotactic factor of anaplylaxis

kininogenase

B-glucosaminidase


MAST CELL

■ GRANULES

• formed only after IgE-mediated release

of granules

Slow-reacting substance of anaphylaxis

(leulcotrienes C4 and D4)

leukotriene B4

platelet activating factor

prostaglandin D2


SUBCUTIS

• also known as panniculus

• beneath the dermis

• composed of lobules of fat cells or lipocytes

separated by fibrous septa composed of

collagen and blood vessels

• collagen of septa is continous with the

collagens of the dermis

• varies in thickness according to site


SUBCUTIS

• provides buoyancy

• functions as:

repository of energy

endocrine organ


SUBCUTIS

■ functions as endocrine organ

•important site of hormone conversion

conversion of androstenedione

into estrone by aromatase

leptin, a hormone that regulates

body weight via the hypothalamus,

is produced in lipocytes

Structures of the Skin

Zharlah Gulmatico-Flores MD, FPDS, FAAD

Epidermal Appendages

• Eccrine glands and ducts

• Apocrine glands and ducts

• Sebaceous glands

• Hair follicles


• ectodermal in origin

• originated as downgrowths from the

epidermis

• contains melanocytes and other cells

seen in the epidermis


• can function as “reserve” epidermis

eg. re-epithelialization after injury to

surface epithelium

due to migration of keratinocytes

from adnexal epithelium along

the skin surface


ECCRINE SWEAT UNIT


ECCRINE SWEAT UNIT

• formed as downgrowth of surface

epidermis during embryogenesis

• composed of 3 sections which are modified

from the basic tubular structure


ECCRINE SWEAT UNIT

composed of:

• Acrosyringium (spiral duct)

• Straight dermal portion

of duct

• Coiled gland


ECCRINE SWEAT UNIT

Acrosyringium (spiral duct)

• the intra-epidermal

component of the unit

• opens directly onto the skin

surface

• derived from dermal duct

cells through mitosis and

upward migration


ECCRINE SWEAT UNIT

Acrosyringium (spiral duct)

• consist of a single layer of

inner or luminal cells and two

to three center row of cells

• cornification takes place

within the duct, and the horn

cells become part of the

stratum corneum of the

epidermis


ECCRINE SWEAT UNIT

Straight dermal portion of

duct

• composed of a double layer

of cuboidal epithelial cells

• lined by eosinophilic cuticle

on the luminal side


ECCRINE SWEAT UNIT

Coiled gland

• secretory acinar portion of the

unit

• found within the panniculus

near the junction of the

dermis and subcutis


Coiled gland

ECCRINE SWEAT UNIT

• inner layer of epithelial cells

(secretory portion of gland)

is surrounded by a layer of

flattened myoepithelial cells


ECCRINE SWEAT UNIT

Coiled gland

• secretory cells are of 2 types:

• pale, glycogen- rich cells

initiate formation

sweat

of

• darker- straining cells

modifies sweat from

isotonic to hypotonic as it

reaches the skin surface


APOCRINE SWEAT UNIT


APOCRINE SWEAT UNIT

• developed as outgrowth of

the infundibular or upper

portion of the hair follicle

(not on the surface of the

epiderms)

• anatomically related

to pilar units


APOCRINE SWEAT UNIT

• composed of:

Straight excretory portion

Coiled secretory gland


APOCRINE SWEAT UNIT

Straight excretory portion

• opens into the infudibular


• composed of a double layer

of cuboidal epithelial cells


APOCRINE SWEAT UNIT


• located at the junction of the

dermis and subcutaneous fat

• lined by a single layer of cells

which vary in appearance

from columnar to cuboidal


APOCRINE SWEAT UNIT


• layer of cells is surrounded by a layer

of myoepithelial cells


APOCRINE SWEAT UNIT


• pieces of columnar cells project

into the lumen of the gland

• in histologic cross-section,

appear as if they are being

extroded (decapitation

secretion)


APOCRINE SWEAT UNIT


• appear more widely dilated than eccrine coils


APOCRINE SWEAT UNIT


• apocrlne sweat stains more

deeply red in H&E sections,

in contrast with the pale pink of

eccrine sweat


APOCRINE SWEAT UNIT

SECRETION:

• appears as milky

• odorless until it reaches the skin

surface where it is altered by

bacteria making it odoriferous

• secretion mediated by adrenergic

innervation and by circulating

adrenomedullary catecholamines


APOCRINE SWEAT UNIT

SECRETION:

• Composition:

protein

carbohydrate

lipid

ammonia

iron


APOCRINE SWEAT UNIT

EXCRETION:

• propulsion of secretion

through the duct is episodic


APOCRINE SWEAT UNIT

FUNCTIONS:

• secretion no known function in man

• do not begin to function until puberty

• in animals:

protective

sexual function

thermoregulation


APOCRINE SWEAT UNIT

LOCATIONS:

• axillae

• areolae

• anogental region

• external auditory canal (cerumminous gland)

• eyelids (glands of moll)


SEBACEOUS GLANDS


SEBACEOUS GLANDS

EMBRYOGENESIS

• formed embryologically as

an outgrowth from the upper



SEBACEOUS GLANDS

• composed of lobules of pale-staining cells

with abundant lipid droplets in their cytoplasm


SEBACEOUS GLANDS

• distribution:

abundant on the face and scalp

distributed throughout all skin sites

absent in palms and soles


SEBACEOUS GLANDS

• anatomically and functionally related to hair

follicles

• always associated with hair follicles except:

tarsal plate of eyelids (Meibomian gland)

buccal mucosa

vermillion border of lip (Fordyce’s spot)

prepuce (Tyson’s glands)

areola (female) (Montgomery’s tubercles)


SEBACEOUS GLANDS

• anatomically and functionally

related to hair follicles


HAIR FOLLICLES


HAIR FOLLICLES

EMBRYOGENESIS

• During embryogenesis,

mesenchymal cells in the fetal

dermis collect immediately

below the basal layer of the

epidermis.

• Epidermal buds grow down into

the dermis at these sites.


HAIR FOLLICLES

EMBRYOGENESIS

• The developing follicle forms

at an angle to the skin surface

and continues its downward

growth.


HAIR FOLLICLES

EMBRYOGENESIS

• At this base, the column of cells widens

forming the bulb and surrounds small

collections of mesenchymal cells.

• These papillary mesenchymal

bodies contain mesenchymal

stem cells with broad functionality.


HAIR FOLLICLES

EMBRYOGENESIS

• along one side of the fetal follicle,

two buds are formed:

• upper bud

develops into the

sebaceous gland

• lower bud

becomes the attachment

for the atrector pili muscle


HAIR FOLLICLES

EMBRYOGENESIS

• third epithelial bud

develops in skin sites

destined to have apocrine

units

develops from the opposite

side of the follicle above the

level of the sebaceous gland


HAIR FOLLICLES

PARTS OF THE HAIR FOLLICLE

• Infundibulum

• Isthmus

• Matrix


HAIR FOLLICLES


• infudibular segment

uppermost portion of the

follicle

extends from the surface

opening to the entrance

of the sebaceous duct

resembles surface epidermis


HAIR FOLLICLES


• isthmus

portion of the follicle

between the sebaceous

duct and the insertion

of the arrector pili muscle


HAIR FOLLICLES


• matrix

inferior portion

includes the lowermost

part of the follicles and

the hair bulb

produce the hair shaft


HAIR FOLLICLES

HAIR GROWTH

• cyclical

• each follicle functions

as an independent unit

HAIR FOLLICLES

ANAGEN CATAGEN TELOGEN


HAIR FOLLICLES

HAIR GROWTH

■ Anagen phase

• active growth phase

• cells of hair bulb actively

divide and produce the

growing hair


HAIR FOLLICLES

HAIR GROWTH

■ Anagen phase

• scalp anagen hairs grow at a

rate of about 0.37 mmlday

• lasts 3-5 years

• 85-90% of scalp hairs


HAIR FOLLICLES

HAIR GROWTH

■ Catagen phase

• transitional phase

• lasts about 2 weeks

• matrix cell stop dividing

• hair develops a brush-like

zone (club hair) due to

incomplete keratinization of

cells


HAIR FOLLICLES

HAIR GROWTH

■ Catagen phase

• lower portion of the follicle

disappears leaving behind a

thin strand of epithelial cells

surrounded by a thick

basement membrane zone


HAIR FOLLICLES

HAIR GROWTH

■ telogen phase

• club hair remains within the

shortened follicle until a new

anagen follicle develops and

the newly formed shaft

dislodges the club hair


HAIR FOLLICLES

HAIR GROWTH

■ telogen phase

• club hair remains within the

shortened follicle until a new

anagen follicle develops and

the newly formed shaft

dislodges the club hair


NAILS


NAILS


NAILS

BASIC NAIL ANATOMY

• nail is a unique structure

• component parts are

collectively called

the nail unit


NAILS

BASIC NAIL ANATOMY

• nail unit consists of the following:

nail matrix

nail bed

hyponychium

proximal nail fold

lateral nail folds


NAILS

BASIC NAIL ANATOMY

• Anatomic structures of the nail include:

proximal nail fold lateral nail folds

nail matrix

lunula

nail bed

onychodermal band

cuticle

hyponychium

nail plate


NAILS


NAILS

NAIL MATRIX

• is the germinative epithelium from

which the nail plate is derived

• There is controversy about whether

the nail bed and nail fold contribute

cells to the

substance of the nail plate.


NAIL

NAIL MATRIX

• is responsible for the majority of

the nail plate substance

• proximal portion of the matrix lies

beneath the nail folds

• distal curved edge can usually be seen

through the nail plate as the white lunula.


NAILS

NAIL MATRIX

• proximal matrix forms the superficial

portion of the nail plate

• distal matrix makes the undersurface

of the nail plate


NAIL

NAIL BED

• nail bed dermis lies beneath the nail plate

• derives its pink color from its rich

vascular supply

• sometimes called the sterile matrix


NAIL

NAIL BED

• probably contributes some cells to the

under surface of the nail plate, allowing the

nail to grow continuously while adhering to

the nail bed


NAIL

NAIL BED

• Longitudinal ridges and grooves are

associated with capillaries oriented in the

longitudinal axis and make up the nail bed

structure.


NAIL

NAIL BED

• extends from the nail matrix

to the hyponychium

• no subcutaneous tissue in the nail bed

• immediately beneath the nail bed lies the periostium

of the distal phalanx


NAILS

NAIL FOLDS

• nail plate is surrounded by the proximal and

lateral nail folds

• surround, support and protect the nail


NAIL

CUTICLE

• is the distal horny end-product of the proximal nail

fold

• adheres to the nail plate

• seals the nail from environmental pathogens and

irritants


NAIL

HYPONYCHIUM

• is the portion of the nail unit that is distal to the nail bed and under the

free edge of the nail plate

• contiguous with the volar skin of the digit


NAIL

HYPONYCHIUM

• hyponychium extends proximally to the distal

groove and onychodermal band

• has a granular layer unlike the matrix and

nail bed, which do not


NAIL

NAIL PLATE

• smooth translucent

structure

• end-product of the

keratinocyte differentiation

in the nail matrix


NAIL

NAIL PLATE

• derives its normal color appearance from the underlying

structures:

pink from the vascular nail bed

white from the lunula(distal part of the

nail matrix) and from air under the free

edge of the nail


NAIL

NAIL PLATE

• bulk of the nail plate comes

from the nail matrix

• damage with scarring to

the matrix can result in a

permanent nail plate

dystrophy, like a split

or ridge


NAIL

NAIL PLATE

• surface of the nail plate is

normally smooth

• may develop longitudinal

ridges as part of the

aging process


NAIL

NAIL PLATE

• hardness is due to the disulfide bonds

found in the keratin in the nail plate

• contains 0.1% calcium, although

calcium contributes little to the

hardness of the nail


NAIL

RATE OF GROWTH

• nails grow continuously,

unlike hair

• fingernails grow at a rate of

approximately 0.1 mm/day or

3mm a month.

• toenails grow at about one-half to

one-third the rate of fingernails.


NAIL

RATE OF GROWTH

• fingernail regenerates in

4–6 months

• toenail regenerates in

8–12 months or more

• certain states affect the rate of nail growth;

for example, nails grow faster during

pregnancy and in psoriasis


NAIL

BLOOD SUPPLY

• nail unit has a rich blood supply

• Lateral digital arteries course down the side

of the digit and form arches that supply

branches to the nail matrix and nail bed.


NAIL

BLOOD SUPPLY

• During nail surgery, hemostasis can be

achieved during the procedure by simply

applying pressure on the sides of the digit

over the digital arteries.


NAIL

NERVE SUPPLY

• sensory nerves course along

the sides of the digit in close

association with the arteries

DERMATOLOGIC

DIAGNOSIS

Zharlah Gulmatico-Flores, MD, FPDS, FAAD

College of Medicine

Primary lesions and surface

characteristics

■ Lesions should be examined carefully.

■ Standing back and viewing a disease process

provides valuable information about the

distribution.

■ Close examination with a magnifying device

provides much more information


characteristics

■ Close examination with a magnifying device

provides much more information


characteristics

■ Often the primary lesion is identified and

the diagnosis is confirmed at this step

■ The physician should learn the surface

characteristics of all the common entities

and gain experience by examining

known entities.

Laboratory Tests

■ Skin biopsy

■ Potassium hydroxide examination

■ Skin scrapings for scabies

■ Gram stain

■ Fungal and bacterial cultures

Laboratory Tests

■ Skin biopsy

Laboratory Tests

■ Cytology (Tzanck test)

■ Wood’s light examination

■ Patch tests

■ Dark field examination

■ Blood tests

A Methodical Approach

■ The skin recommended approach to the

patient with skin disease is as follows:

- History

- Distribution

- Primary lesion

- Differential diagnosis


■ HISTORY

• Obtain a brief history, noting:

duration

date of onset

location

symptoms

family history

allergies

occupation

previous treatment


■ DISTRIBUTION

• Determine the extent of the eruption by

having the patient disrobe completely.


■ PRIMARY LESION

• Determine the primary lesion.

• Examine the lesions carefully.

• A hand lens is a valuable aid for

studying skin lesions.

• Determine the nature of any

secondary or special lesions.


■ DIFFERENTIAL DIAGNOSIS

• Formulate a differential diagnosis.

Examination Technique

■ DISTRIBUTION

• The skin should be examined methodically.

• An eye scan over wide areas is inefficient.

• It is most productive to mentally divide the

skin surface into several sections.


■ DISTRIBUTION

• Carefully study each section.

• For example, when studying the face,

examine the area:

around each eye

nose

mouth

cheeks

temples


■ DISTRIBUTION

• During an examination, patients may show

small areas of the skin, tell the doctor that

the rest of the eruption looks the same,

and expect an immediate diagnosis.

• The rest of the eruption may or

may not look the same.


■ DISTRIBUTION

• Rest of the eruption may or

may not look the same

• Patients with rashes should received a

complete skin examination to determine

the distribution and confirm the diagnosis

Diagnostic Details of Lesions

■ DISTRIBUTION

● Lesions may be few or numerous

● In arrangement, they may be discrete

or may coalesce to form patches of

peculiar configurations


■ DISTRIBUTION

● They may appear over the entire

body, sometimes following the lines

of cleavage, or they may follow the

course of nerves, as in herpes zoster


■ SYMMETRY

● Remarkable degree of bilateral

symmetry is characteristic of

- Dermatitis herpetiformis

- Vitiligo

- Herpes gestationis


■ CONFIGURATION

● Some lesions assume characteristic

figures, either by enlargement

or by coalescence

Tinea corporis Pityriasis rubra pilaris Tinea corporis


■ CONFIGURATION

● Circinate and Annular Lesions

Dermatophytosis

Erythema annulare

centrifugum

Syphilis


■ CONFIGURATION

● Circinate and Annular lesions

Lichen planus

Psoriasis

Ertythema multiforme


■ CONFIGURATION

● Circinate and Annular lesions

Seborrheic dermatitis Pityriasis rosea Nummular dermatitis


■ CONFIGURATION

● Gyrate patterns are formed in:

Erythema gyratum repens

Tinea imbricata

Psoriasis


■ CONFIGURATION

● Gyrate patterns are formed in:

Mycosis fungoides


■ CONFIGURATION

● Serpiginous border

Dermatophytosis

Cutaneous larva migrans


■ CONFIGURATION

● grotesque and bizarre patterns

Mycosis fungoides


■ CONFIGURATION

● grotesque and bizarre patterns

Dermatitis artefacta


■ COLOR

● Color of the skin is due to:

melanin

oxyhemoglobin

reduced hemoglobin

carotene


■ COLOR

● Factors that affect the color are:

proportions of the components

(melanin, carotene, oxyhemoglobin, reduced hemoglobin)

their depth within the skin

thickness of the epidermis

hydration of the skin


■ COLOR

● Tyndall effect

modifies the color of the skin and

the color of lesions by the selective

scattering of light waves of different

wavelengths


■ COLOR

● Tyndal leffect

example of this light dispersion

effect are:

Mongolian spots


■ COLOR

● it is not advisable to place too much

reliance on the color of lesions as a

diagnostic factor

difficult to describe colors

colors appear differently to

different individuals

scarlet fever


■ COLOR

● may serve as a corroborative aid

● characteristic color is of diagnostic aid in:

Mycosis fungoides

Juvenile xanthogranuloma


■ COLOR



Erysipelas

Scarlet fever


■ COLOR



erythema multiforme

xanthoma

secondary syphilis

lupus vulgaris

many other diseases


■ COLOR

● patches lighter in color than the normal

skin color (hypopigmented) suggests:

▪ tinea versicolor

▪ nevus anemicus

▪ leprosy

▪ idiopathic guttate hypomelanosis

▪ hypomelanotic macules of

tuberous sclerosis

▪ Seborrheic dermatitis


■ COLOR

● patches may be light in

Pityriasis versicolor

Pityriasis alba


■ COLOR

● actual depigmentation

Nevus depigmentosus Vitiligo Halo nevus


■ COLOR

● actual depigmentation

Linear scleroderma

En coup de sabre

Morphea

▪ lentigines

▪ nevi


■ COLOR

● darkening may be due to

Inflammation

Melasma

▪ melasma


■ COLOR

● darkening may be due to

Ephelids

Lentigines

Nevi


■ COLOR

● result of pressure or rubbing

● deposits of metals such as

▪ silver

▪ mercury

▪ gold


■ GROUPING

● Certain lesions tend to be grouped in:

▪ clusters

Herpes zoster


■ GROUPING


▪ concentric manner as in “iris” lesions

Erythema multiforme


■ GROUPING


▪ Corymbose arrangement

- small lesions arranged around

a large one


■ GROUPING


▪ Corymbose arrangement

Psoriasis in HIV Borderline Tuberculoid Syphilis in HIV

Leprosy


■ GROUPING


▪ Cockade pattern

- rings within concentric rings

Erythema multiforme

Tinea circinata

Borderline leprosy


■ GROUPING

● characteristic of:

Herpes simplex

Herpes zoster


■ GROUPING

● characteristic of Dermatitis hepetiformis


■ EVOLUTION

● Some lesions quickly attain complete

formation without any intermediate stage

(macules)

● Certain lesions remain the same during

their entire existence (warts)


■ EVOLUTION

● Polymorphous eruption

lesions succeed one another in a

series of crops

with lesions in various stages of

development or involution all present

at the same time


■ EVOLUTION


Varicella


■ EVOLUTION


Dermatitis herpetiformis


■ INVOLUTION

● certain lesions disappear completely

● other leave pigment or scars

● others do not involute


■ CONSISTENCY

● Palpation is an essential part of the

physical examination of lesions

● Does the lesion blanch on pressure?

-if not, it may be a purpuric lesion


■ CONSISTENCY

● Is lesion fluctuant?

- if so, it may have free fluid in it

● Is the lesion cold? Hot?

● If there is a nodule or tumor, does it sink

through a ring into the panniculus?

- nuerofibroma


■ CONSISTENCY

● Does the skin dimple when the lesions is

picked up and compressed laterally?

- Fitzpatrick’s “dimple sign”

- suggestive of histiocytoma

● Is the lesion hard or merely very firm?

- calcification or fibroma

Physical examination of

SKIN LESIONS

■ Number

■ Color

■ Shape, symmetry, configuration

■ Primary lesion

■ With or without secondary lesion

■ With or without tenderness

■ Site

Thank you

1.-Introduction-to-the-genral-deramtology

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?