4. The Skin

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The Skin

C H A P T E R

The Skin 44

C H A P T E R 4 s T H E S K I N 95

ANATOMY AND PHYSIOLOGY

The major function of the skin is to keep the body in homeostasis despite thedaily assaults of the environment. It provides boundaries for body fluids while

protecting underlying tissues from microorganisms, harmful substances, andradiation. It modulates body temperature and synthesizes vitamin D.

The skin is the heaviest single organof the body, accounting for approx-imately 16% of body weight andcovering an area of roughly 1.2 to2.3 meters squared. It contains threelayers: the epidermis, the dermis,and the subcutaneous tissues.

The most superficial layer, the epi-

dermis, is thin, devoid of blood ves-sels, and itself divided into two lay-ers: an outer horny layer of deadkeratinized cells and an inner cellularlayer where both melanin and ker-atin are formed.

The epidermis depends on the un-derlying dermisfor its nutrition. Thedermis is well supplied with blood. Itcontains connective tissue, seba-ceous glands, sweat glands, and hair

follicles. It merges below with sub-cutaneous tissue, or adipose, alsoknown as fat.

Hair, nails, and sebaceousand sweat glandsare considered appendages of theskin. Adults have two types of hair: vellus hair,which is short, fine, incon-spicuous, and relatively unpigmented; and terminal hair,which is coarser,thicker, more conspicuous, and usually pigmented. Scalp hair and eyebrowsare examples of terminal hair.

Hair shaft

Horny layer

Cellular layer

Sebaceousgland

Muscle thaterects hair shaft

Sweat gland

Hair follicle

Vein

Nerve

Artery

Duct ofsweat gland

Epidermis

Dermis

Subcutaneoustissue

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Nails protect the distal ends of the fingers and toes. The firm, rectangular,and usually curving nail plategets its pink color from the vascular nail bedto which the plate is firmly attached. Note the whitish moon ( lunula) andthe free edge of the nail plate. Roughly a fourth of the nail plate (the nailroot) is covered by theproximal nail fold. The cuticleextends from this foldand, functioning as a seal, protects the space between the fold and the plate

from external moisture. Lateral nail foldscover the sides of the nail plate.Note that the angle between the proximal nail fold and the nail plate is nor-mally less than 180.


96 B A T E S G U I D E T O P H Y S I C A L E X A M I N A T I O N A N D H I S T O R Y T A K I N G

Lateralnail fold Lunula

Proximalnail fold

Nail plate CuticleFreeedge

Fingernails grow at about 0.1 mm daily; toenails grow more slowly.

Sebaceous glandsproduce a fatty substance that is secreted to the skin surfacethrough the hair follicles. These glands are present on all skin surfaces exceptthe palms and soles. Sweat glandsare of two types: eccrine and apocrine. The

eccrine glandsare widely distributed, open directly onto the skin surface, andby their sweat production help to control body temperature. In contrast, theapocrine glandsare found chiefly in the axillary and genital regions, usuallyopen into hair follicles, and are stimulated by emotional stress. Bacterial de-composition of apocrine sweat is responsible for adult body odor.

The color of normal skin depends primarily on four pigments: melanin,carotene, oxyhemoglobin, and deoxyhemoglobin. The amount ofmelanin,the brownish pigment of the skin, is genetically determined and is increasedby sunlight. Caroteneis a golden yellow pigment that exists in subcutaneousfat and in heavily keratinized areas such as the palms and soles.

Hemoglobin, which circulates in the red cells and carries most of the oxygenof the blood, exists in two forms. Oxyhemoglobin, a bright red pigment, pre-dominates in the arteries and capillaries. An increase in blood flow throughthe arteries to the capillaries of the skin causes a reddening of the skin, whilethe opposite change usually produces pallor. The skin of light-colored per-sons is normally redder on the palms, soles, face, neck, and upper chest.

As blood passes through the capillary bed, some of the oxyhemoglobin losesits oxygen to the tissues and changes to deoxyhemoglobina darker and

Nail root

Proximal nail fold

Nail plate

Cross sectionof nail plate

Nail bedDistal phalanx

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somewhat bluer pigment. An increased concentration of deoxyhemoglobinin cutaneous blood vessels gives the skin a bluish cast known as cyanosis.

Cyanosis is of two kinds, depending on the oxygen level in the arterial blood.If this level is low, cyanosis is central. If it is normal, cyanosis isperipheral.Peripheral cyanosis occurs when cutaneous blood flow decreases and slows,

and tissues extract more oxygen than usual from the blood. Peripheralcyanosis may be a normal response to anxiety or a cold environment.

Skin color is affected not only by pigments but also by the scattering of lightas it is reflected back through the turbid superficial layers of the skin or ves-sel walls. This scattering makes the color look more blue and less red. Thebluish color of a subcutaneous vein is a result of this effect; it is much bluerthan the venous blood obtained on venipuncture.

Changes With Aging

As people age their skin wrinkles, becomes lax, and loses turgor. The vascu-larity of the dermis decreases and the skin of light-skinned persons tends tolook paler and more opaque. Comedones (blackheads) often appear on thecheeks or around the eyes. Where skin has been exposed to the sun it looksweatherbeaten: thickened, yellowed, and deeply furrowed. Skin on the backsof the hands and forearms appears thin, fragile, loose, and transparent, andmay show whitish, depigmented patches known as pseudoscars. Well-demarcated, vividly purple macules or patches, termed actinic purpura, mayalso appear in the same areas, fading after several weeks. These purpuric spotscome from blood that has leaked through poorly supported capillaries andhas spread within the dermis. Dry skin (asteatosis)a common problemisflaky, rough, and often itchy. It is frequently shiny, especially on the legs,where a network of shallow fissures often creates a mosaic of small polygons.

Some common benign lesions often accompany aging: cherry angiomas(p. __), which often appear early in adulthood, seborrheic keratoses (p. __),and, in sun-exposed areas, actinic lentigines or liver spots (p. __) and ac-tinic keratoses (p. __). Elderly people may also develop two common skincancers: basal cell carcinoma and squamous cell carcinoma (p. __).

Nails lose some of their luster with age and may yellow and thicken, espe-cially on the toes.

Hair on the scalp loses its pigment, producing the well-known graying. Asearly as 20, a mans hairline may start to recede at the temples; hair loss atthe vertex follows. Many women show a less severe loss of hair in a similarpattern. Hair loss in this distribution is genetically determined.

In both sexes, the number of scalp hairs decreases in a generalized pattern,and the diameter of each hair diminishes.

Less familiar, but probably more important clinically, is the normal hairloss elsewhere on the body: the trunk, pubic areas, axillae, and limbs.



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These changes will be discussed in later chapters. Coarse facial hairs appearon the chin and upper lip of many women by about the age of 55, but donot increase further thereafter.

Many of the observations described here pertain to lighter-skinned personsand do not necessarily apply to others. For example, Native American men

have relatively little facial and body hair compared to lighter-skinned men,and should be evaluated according to their own norms.

HEALTH PROMOTION AND COUNSELING


Causes of generalized itching

without obvious reason include dry

skin, aging, pregnancy, uremia,

jaundice, lymphomas and

leukemia, drug reaction, and lice.

EXAMPLES OF ABNORMALITIES

Common or Concerning Symptoms

s Hair losss Rash

s Moles

Start your inquiry about the skin with a few open-ended questions: Haveyou noticed any changes in your skin?. . . your hair? . . . your nails?. . .Have you had any rashes? . . . sores? . . . lumps? . . . itching? Have younoticed any moles that have changed in appearance? Where? When?

It is usually best to defer further questions about the skin until the physical

examination, when you can see what the patient is talking about.

THE HEALTH HISTORY

HEALTH PROMOTION AND COUNSELING

Important Topics for Health Promotion and Counseling

s Risk factors for melanoma

s Avoidance of excessive sun exposure

Clinicians play an important role in counseling patients about protectivemeasures for skin care and the hazards of excessive sun exposure. Basal celland squamous cell carcinomas are the most common cancers in the UnitedStates and are found most frequently in sun-exposed areas, particularlythe head, neck, and hands. Malignant melanoma, although rare, is the mostrapidly increasing U.S. malignancy, now occurring in 1 in 74 Americans.Although melanoma often arises in nonsun-exposed areas, it is associated

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TECHNIQUES OF EXAMINATION EXAMPLES OF ABNORMALITIES


Pallor due to decreased redness is

seen in anemia and in decreased

blood flow, as in fainting or arterialinsufficiency.

Causes of central cyanosis include

advanced lung disease, congenital

heart disease, and abnormal

hemoglobins.

Cyanosis in congestive heart fail-

ure is usually peripheral, reflecting

decreased blood flow, but in pul-monary edema it may also be cen-

tral. Venous obstruction may cause

peripheral cyanosis.

Jaundice suggests liver disease or

excessive hemolysis of red blood

cells.

Artificial light often distorts colors

and masks jaundice.

See Table 4-1, Basic Types of Skin

Lesions (pp. ____), and Table 4-2,

Skin Colors (p. __).

TECHNIQUES OF EXAMINATION

Observe the skin and related structures during the General Survey and

throughout the rest of your examination. The entire skin surface should beinspected in good light, preferably natural light or artificial light that re-sembles it. Correlate your findings with observations of the mucous mem-branes. Diseases may manifest themselves in both areas, and both are neces-sary for assessing skin color. Techniques of examining these membranes aredescribed in later chapters.

To make your observations more astute, acquaint yourself now with someof the skin lesions and colors that you may encounter.

Skin

Inspect and palpate the skin. Note these characteristics:

Color. Patients may notice a change in their skin color before the clini-cian does. Ask about it. Look for increased pigmentation (brownness), lossof pigmentation, redness, pallor, cyanosis, and yellowing of the skin.

The red color of oxyhemoglobin and the pallor due to a lack of it are bestassessed where the horny layer of the epidermis is thinnest and causes the

least scatter: the fingernails, the lips, and the mucous membranes, particu-larly those of the mouth and the palpebral conjunctiva. In dark-skinned per-sons, inspecting the palms and soles may also be useful.

Central cyanosis is best identified in the lips, oral mucosa, and tongue. Thelips, however, may turn blue in the cold, and melanin in the lips may simu-late cyanosis in darker-skinned people.

Cyanosis of the nails, hands, and feet may be central or peripheral in origin.Peripheral cyanosis may be caused by anxiety or a cold examining room.

Look for the yellow color of jaundice in the sclera. Jaundice may also appearin the palpebral conjunctiva, lips, hard palate, undersurface of the tongue,tympanic membrane, and skin. To see jaundice more easily in the lips, blanchout the red color by pressure with a glass slide.

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For the yellow color that accompanies high levels of carotene, look at thepalms, soles, and face.

Moisture. Examples are dryness, sweating, and oiliness.

Temperature. Use the backs of your fingers to make this assessment. Inaddition to identifying generalized warmth or coolness of the skin, note thetemperature of any red areas.

Texture. Examples are roughness and smoothness.

Mobility and Turgor. Lift a fold of skin and note the ease with whichit lifts up (mobility) and the speed with which it returns into place (turgor).

Lesions. Observe any lesions of the skin, noting their characteristics:

s Their anatomic location and distributionover the body. Are they gener-alized or 1ocalized? Do they, for example, involve the exposed surfaces,the intertriginous (skin fold) areas, or areas exposed to specific allergensor irritants such as wrist bands, rings, or industrial chemicals?

s Their arrangement. For example, are they linear, clustered, annular (in aring), arciform (in an arc), or dermatomal (covering a skin band that cor-

responds to a sensory nerve root; see pp. ____)?

s The type(s) of skin lesions(e.g., macules, papules, vesicles, nevi). If possi-ble, find representative and recent lesions that have not been traumatizedby scratching or otherwise altered. Inspect them carefully and feel them.

s Their color.

EVALUATING THE BEDBOUND PATIENT

People who are confined to bed, especially when they are emaciated, elderly,or neurologically impaired, are particularly susceptible to skin damage andulceration. Pressure soresresult when sustained compression obliterates arte-riolar and capillary blood flow to the skin. Sores may also result from theshearing forces created by bodily movements. When a person slides down inbed from a partially sitting position, for example, or is dragged rather thanlifted up from a supine position, the movements may distort the soft tissuesof the buttocks and close off the arteries and arterioles within. Friction andmoisture further increase the risk.

Carotenemia

Dryness in hypothyroidism; oiliness

in acne

Generalized warmth in fever,

hyperthyroidism; coolness in

hypothyroidism. Local warmth of

inflammation or cellulitis

Roughness in hypothyroidism

Decreased mobility in edema,

scleroderma; decreased turgor in

dehydration

Many skin diseases have typical

distributions. Acne affects the

face, upper chest, and back;

psoriasis, the knees and elbows

(among other areas); and

Candidainfections, the inter-

triginous areas.

Vesicles in a unilateral dermatomal

pattern are typical of herpes zoster.

See Table 4-1, Basic Types of Skin

Lesions (pp. ____); Table 4-3,

Vascular and Purpuric Lesions of

the Skin (p. __); Table 4-4, Skin

Tumors (p. __); and Table 4-5, Be-

nign and Malignant Nevi (p.__).

See Table 4-6, Pressure Ulcers(p. __).

EXAMPLES OF ABNORMALITIESTECHNIQUES OF EXAMINATION


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Local redness of the skin warns of

impending necrosis, although

some deep pressure sores develop

without antecedent redness. Ulcers

may be seen.

See Table 4-7, Findings In or Near

the Nails (pp. ____).

Alopeciarefers to hair lossdiffuse,patchy, or total.

Sparse hair in hypothyroidism; fine

silky hair in hyperthyroidism

See Table 4-8, Skin Lesions in Con-

text (pp. ____).

TECHNIQUES OF EXAMINATION EXAMPLES OF ABNORMALITIES


Hair

Inspect and palpate the hair. Note its quantity, distribution, and texture.

Skin Lesions in Context

After familiarizing yourself with the basic types of lesions, review their ap-pearances in Table 4-8 and in a well-illustrated textbook of dermatology.Whenever you see a skin lesion, look it up in such a text. The type of lesions,their location, and their distribution, together with other information from

the history and the examination, should equip you well for this search and,in time, for arriving at specific dermatologic diagnoses.

Assess every susceptible patient by carefully inspecting the skin that overliesthe sacrum, buttocks, greater trochanters, knees, and heels. Roll the patientonto one side to see the sacrum and buttocks.

Nails

Inspect and palpate the fingernails and toenails. Note their color and shape,and any lesions. Longitudinal bands of pigment may be seen in the nails ofnormal people who have darker skin.

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TABLE 4-1 s Basic Types of Skin Lesions


TABLE4-

1

s

BasicTypesofSkinLesions

PrimaryLesions(MayAriseFromPreviouslyNormalSkin)

Circumscribed,

Flat,N

onpalpable

ChangesinSkinColor

MaculeSmallflatspot,up

to1.0

cm

Examp

les:freckle,petechia

Patch

Flatspot,1.0cmor

larger

PalpableElevatedSolidMasses

PapuleUpto1.0cm.

Example:anelevatednevus

PlaqueElevatedsuperficial

lession1.0cmorlarger,

oftenformedbycoalescence

ofpapules

NoduleMarble-l

ikelesion

largerthan0.5cm,often

deeperandfirmerthana

papule

WhealAsomewhat

irregular,relativelytransient,

superficialareaoflocalized

skinedema.Examples:

mosquitobite,hive

CircumscribedSuperficia

lElevationsof

theSkinFormedbyFree

Fluidina

CavityWithintheSkinLa

yers

VesicleU

pto1.0cm;filled

withserou

sfluid.

Example:

herpessim

plex

Bulla1.0cmorlarger;

filledwith

serousfluid.

Example:2nd-degreeburn

PustuleFilledwithpus.

Examples:acne,impetigo

SecondaryLesions(ResultFromChangesinPrima

ryLesions)

LossofSkinSurface Er

osion

Lossofthe

superfi

cialepidermis;surface

ismoistbutdoesnotbleed.

Examp

le:moistareaafterthe

ruptureofavesicle,asin

chickenpox

MaterialontheSkinS

urface

Crust

Thedriedresidueof

serum,pus,orblood.

Examp

le:impetigo

UlcerAdeeperlossof

epidermisanddermis;may

bleedandscar.

Examples:

stasisulcerofvenous

insufficiency,syphilitic

chancre

FissureA

linearcrackin

theskin.E

xample:athletes

foot

ScaleAthinflakeof

exfoliatedepidermis.

Examples:dandruff,

dryskin

,

psoriasis

(tablecontinuesnextpage)

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TABLE 4-1 s Basic Types of Skin Lesions


TABLE4-

1

s

BasicTypesofSkinLesions(C

ontinued)

MiscellaneousLesions

ExcoriationAnabrasionorscratch

mark.Itmaybelinear

,asillustrated,or

rounded,asinascratc

hedinsectbite.

ScarReplacementof

destroyedtissuebyfibrous

tissue.Maybethickan

d

pink(hypertrophic)or

thin

andwhite(atrophic),but

doesnotextendbeyon

d

theinjuredarea

BurrowofScabiesAperson

withscabieshas

intenseitching.

Skinlesionsincludesmall

papules,pustules,lichenified

areas,and

excoriations.Withamagnifyinglens,lookfor

theburrowofthemitethatc

ausesit.

A

burrowisaminute,slightlyraisedtunnelin

theepidermisandiscommonlyfoundonthe

fingerwebsandonthesides

ofthefingers.It

lookslikeashort(51

5mm),linearorcurved,

graylineandmayendinatinyvesicle.

AdditionalTerms:

s

ComedoThecommon

blackheadthatmarksthepluggedopeningofasebaceousgland,

frequentlyseenwithacne

s

NevusThecommonm

ole;appearsflattoslightlyelevated,rou

ndandevenlypigmented;however,som

enevilookquitedifferent,asinthepigmentedneviof

melanoma.

s

TelangiectasiasDilated

smallvessels(canbevenules,arterioles,

includingspiderangiomas,orcapillaries)thatlookeitherredorbluish.

Mayappearby

themselvesoraspartsof

otherlesions,asinabasalcellcarcinom

aorradiodermatitis(skininjuryfromio

nizingradiation).

(Sourcesofphotos:Lichenification,Excoriation,Scar,BurrowofScabiesGoodheartHP:APhotoguideofCommonS

kinDisorders:DiagnosisandManagement.

Philadelphia,

LippincottWilliams&Wilkins,1999;AtrophyFitzpatrickJE,

AelingJL:

DermatologySecretsinColor,2nded.

Phila

delphia,

LippincottWilliams&Wilkins,200

0)

LichenificationThickenin

gand

rougheningoftheskinwithincreased

visibilityofthenormalskin

furrows.

Example:atopicdermatitis

Atroph

yThinningoftheskinwithloss

ofthe

normalskinfurrows;theskinlooks

shinierandmoretranslucentthannormal.

Example:arterialinsufficiency

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TABLE 4-3 s Vascular and Purpuric Lesions of the Skin


TABLE4-

3

s

Vasc

ularandPurpuricLesionsoftheSkin

Vascular

Purpuric

Spider

Angioma

SpiderVein

CherryAngioma

Petechia/Purpura

Ecchymosis

Color

Size

Shape

Pulsatility

Effectof

Pressure

Distribution

Significance

Fieryre

d

Fromverysmallto

2cm

Centralbody,

sometim

esraised,

surroun

dedby

erythem

aand

radiatin

glegs

Oftend

emonstrablein

thebod

yofthespider,

whenpressurewitha

glassslideisapplied

Pressureonthebody

causesb

lanchingof

thespid

er.

Face,neck,arms,and

uppertrunk;almost

neverbelowthewaist

Liverdisease,

pregnan

cy,vitaminB

deficien

cy;alsooccurs

normallyinsome

people

Bluish

Variable,

fromvery

small

toseveralinches

Variable.

Mayresemblea

spiderorbelinear,

irregular,cascading

Absent

Pressureoverthecenter

doesnotcauseblan

ching,

butdiffusepressure

blanchestheveins.

Mostoftenonthelegs,

nearveins;alsoonthe

anteriorchest

Oftenaccompanies

increasedpressureinthe

superficialveins,as

in

varicoseveins

Brightorrubyred;

maybecomebrownish

withage

13mm

Round,

flator

sometimesraised,may

besurroundedbya

palehalo

Absent

Mayshowpartial

blanching,especiallyif

pressureisappliedwith

theedgeofapinpoint

Trunk;alsoextremities

None;increaseinsize

andnumberswith

aging

Deepredorreddish

purple,

fadingawayover

time

Petechia,

13mm;

purpura,

larger

Rounded,sometimes

irregular;flat

Absent

None

Variable

Bloodoutsidethevessels;

maysuggestableeding

disorderor,ifpetechiae,

embolitoskin

Purpleorpurplishblue,

fadingtogreen,yellow,

andb

rownwithtime

Variable,

largerthan

petechiae

Rounded,oval,or

irregu

lar;mayhavea

centralsubcutaneousflat

nodule(ahematoma)

Absent

None

Variable

Blood

outsidethe

vessels;oftensecondary

tobruisingortrauma;

alsoseeninbleeding

disorders

(Sourcesofphotos:SpiderAng

iomaMarksR:SkinDiseaseinOldAge.Philadelphia,

JBLippincott,

1987;Petechia/PurpuraKelleyWN:TextbookofInternalMe

dicine.Philadelphia,

JBLippincott,

1989)

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TABLE 4-4 s Skin Tumors


TABLE4-

4

s

Skin

Tumors

BasalCellCarcinoma

Abasalcellcarcinoma,thoughmalignant,grows

slowlyandseldommetastasizes.Itismost

commoninfair-s

kinnedad

ultsoverage40,and

usuallyappearsontheface.

Aninitialtranslucent

nodulespreads,leavingad

epressedcenteranda

firm,elevatedborder.

Telangiectaticvesselsare

oftenvisible.

Squamo

usCellCarcinoma

Squamouscellcarcinomausuallyappearsonsun-

exposedskinoffair-s

kinnedadultsover60.

Itmay

developin

anactinickeratosis.Itusuallygrows

morequic

klythanabasalcellcarcinoma,isfirmer,

andlooks

redder.

Thefaceandthebackofthe

handareo

ftenaffected,asshownhere.

KaposisSarcomainAIDS

WhenKaposissarcoma,amalign

anttumor,

accompaniesAIDS,

itmayappearinmanyforms:

macules,papules,plaques,ornodulesalmost

anywhereonthebody.Lesionsa

reoftenmultiple

andmayinvolveinternalstructur

es.

Ontheleftare

ovoid,pinkishredplaquesthattypicallylengthen

alongtheskinlines.

Theymaybecomepigmented.

Ontherightisapurplishrednoduleonthefoot.

SeborrheicKeratosis

Seborrheickeratosesarecommon,

benign,

yellowishtobrown,raisedlesionsthatfeelslightly

greasyandvelvetyor

warty.

Typicallymultipleand

symmetricallydistribu

tedonthetrunkofolder

people,theymayalso

appearonthefaceand

elsewhere.Inblackpeople,oftenyoungerwomen,

theymayappearassm

all,deeplypigmented

papulesonthecheeksandtemples(dermatosis

papulosanigra).

(Sourcesofphotos:BasalCell

Epithelioma:RapiniR.SquamousCellCarcinoma,ActinicKeratosis,andSeborrheicKeratosisSauerGC:ManualofSkinDiseases,5thed.Philadelphia,JB

Lippincott,1985;KaposisSarcomainAIDSDeVitaVTJr,HellmanS,RosenbergSA[eds]:AIDS:Etiology,Diagnosis

,Treatment,andPrevention.Philadelphia,JBLippincott,1985)

ActinicKeratosis

Actinickeratosesaresuperficial,

flatten

edpapules

coveredbyadryscale.Oftenmultiple,theymay

beroundorirregular,andarepink,tan,or

grayish.

Theyappearonsun-exposedskinofolder,

fair-s

kinnedpersons.Thoughthemselvesbenign,

theselesionsmaygiverisetosquamou

scell

carcinoma(suggestedbyrapidgrowth

,induration,

rednessatthebase,andulceration).Keratoseson

faceandhand,typicallocations,aresh

own.

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TABLE 4-5 s Benign and Malignant Nevi


TABLE4-

5

s

BenignandMalignantNevi

BenignNevus

Thebenignnevus,orcomm

onmole,usuallyappearsin

thefirstfewdecades.

Severalnevimayariseatthesame

time,buttheirappearanceusuallyremainsunchanged.

Notethefollowingtypicalfeaturesandcontrastthem

withthoseofatypicalneviandmelanoma:

s

Roundorovalshape

s

Sharplydefinedborders

s

Uniformcolor,especially

tanorbrown

s

Diameter6mm(Fig.

C)

s

Elevation,thoughalsomaybeflat(Fig.

C).

Reviewmelanomariskfactorssuchasintenseyear-

roundsunexposure,

blisteringsunburnsin

childhood,

fairskinthatfrecklesorburnseasily

(especiallyifblondorredhair),

familyhistoryof

melanoma,andnevithatarechangingoratypical,

especiallyif>50.

Changingnevimayhavenew

swellingorrednessbeyondtheborder,scaling,

oozing,orbleeding,orsensatio

nssuchasitching,

burning,orpain.

Ondarkerskin,

lookformelano

masunderthe

nails,onthehands,orontheso

lesofthefeet.

(CourtesyofAmericanCancerSociety;AmericanAcademyofDermatolog

y)

Malig

nantMelanoma

LearntheABCDEsofmelanomafromthese

referen

cestandardphotographsfromthe

AmericanCancerSociety:

A

B

C

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TABLE 4-7 s Findings In or Near the Nails


TABLE4-

7

s

Find

ingsinorNeartheNails

ClubbingoftheFingers

Inclubbing,thedistalphalanxofeachfingerisroundedandbulbo

us.Thenail

plateismoreconvex,andt

heanglebetweentheplateandtheproximalnail

foldincreasesto180orm

ore.

Theproximalnailfold,whenpalpa

ted,

feels

spongyorfloating.

Causes

aremany,includingchronichypoxiafro

mheart

diseaseorlungcancerandhepaticcirrhosis.

Paronychia

Aparonychiaisaninfl

ammationoftheproximalandlateralnailfolds.Itmaybe

acuteor,asillustrated,chronic.

Thefoldsarered,swollen,an

doftentender.

Thecuticlemaynotb

evisible.

Peoplewhofrequentlyimmersetheirnailsin

waterareespeciallysusceptible.

Multiplenailsareoftenaffected.

Onycholysis

Onycholysisreferstoapainlessseparationofthenailplatefromt

henailbed.

Itstartsdistally,enlarging

thefreeedgeofthenailtoavaryingdegree.

Severalorallnailsareusua

llyaffected.

Causesaremany.

TerrysNails

Terrysnailsaremostlywhitishwithadistalbandofreddishbrown.

Thelunulae

ofthenailsmaynotbevisible.

Thesenailsmaybeseenwithagingandinpeople

withchronicdiseasess

uchascirrhosisoftheliver,congestiveh

eartfailure,and

non-insulin-dependentdiabetes.

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TABLE 4-7 s Findings In or Near the Nails


WhiteSpots(Leukony

chia)

Traumatothenailsiscommonlyfollowedbywhitespotsthatgrowslowlyout

withthenail.Spotsinthepatternillustratedaretypicalofoverlyvigorousand

repeatedmanicuring.

Thecurvesinthisexampleresemblethecurv

eofthe

cuticleandproximalnailfo

ld.

TransverseWhite

Lines(MeesLines)

Thesearetransverselines,notspots,andtheircurvesaresim

ilartothoseof

thelunula,notthecu

ticle.Theseuncommonlinesmayfollo

wanacuteor

severeillness.Theyem

ergefromundertheproximalnailfoldsandgrowout

withthenails.

Psoriasis

Smallpitsinthenailsmaybeearlysignsofpsoriasisbutarenotspecificforit.

Additionalfindings,notshownhere,includeonycholysisandacircumscribed

yellowishtandiscoloration

knownasanoilspotlesion.

Markedthickeningof

thenailsmaydevelop.

BeausLines

Beauslinesaretransversedepressionsinthenailsassociatedw

ithacutesevere

illness.Thelinesemer

gefromundertheproximalnailfoldsw

eekslaterand

growgraduallyoutwiththenails.

AswithMeeslines,cliniciansmaybeableto

estimatethetimingofacausalillness.

(Sourcesofphotos:ClubbingoftheFingers,Paronychia,Onycholyis,TerrysNails

HabifTP:ClinicalDermatology:AC

olorGuidetoDiagnosisandTherapy,2nded.

St.Louis,

CV

Mosby,1990;WhiteSpots,Tra

nsverseWhiteLines,Psoriasis,BeausLinesSamsWMJr,

LynchPJ:PrinciplesandPract

iceofDermatology.NewYork,

ChurchillLivingstone,1990)

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TABLE 4-8 s Skin Lesions in Context


TABLE4-

8

s

Skin

LesionsinContext

Thistableshowsavarietyo

fprimaryandsecondaryskinlesions.Try

toidentifythem,includingthoseindicatedbyletters,

beforereadingtheaccompanyingtext.

Maculesonthedorsumof

thehand,wrist,

andforearm(actiniclentigines)

Pustulesonthepalm(inpustularpsoriasis)

Vesiclesonthechin(inpemphigus)

(A)Bulla(inerythemamultiforme),

(B)target(oriris)lesion

(A)T

elangiectasia,

(B)nodule,

(C)ulcer(in

squamouscell

carcinoma)

BC

A

Papulesontheknee(inlichenplanus)

A

B

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TABLE 4-8 s Skin Lesions in Context


Wheals(urticaria)inadrugeruption

inaninfant

(A)Patch,

(B)nodulesa

combinationtypicalof

neurofibromatosis.Thispatchisa

caf-au-laitspot.

A

B

B

(A)Vesicle,

(B)pustule,

(C)erosions,(D)crust,on

thebackofaknee(ininfectedatopicdermatitis)

A

B

DC

Plaqueswithscalesonthefrontofa

knee(inpsoriasis)

(A)Excoriation,

(B)lichenificationon

theleg

(inatopicdermatitis)

A

B

(SourceofallphotosexceptforMacules:SauerGC:ManualofSkinDiseases,5thed.

Philadelphia,

JBLippincott,

1985)

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