Drug Eruptionrug Eruption

Definition

Drug eruption :Drug eruption : various kinds of drugs delivered into human body by kinds of means create the cutaneous and mucosal reaction.

Drugs delivered by kinds Drugs delivered by kinds of meansof means

OralOral Injections (subcutaneous\intramuscularly\intraInjections (subcutaneous\intramuscularly\intra

venous)venous) External use ( eye dropsExternal use ( eye drops 、、 nasal drops)nasal drops) InhalationInhalation BuccalBuccal GargleGargle Embolism( anus suppositoryEmbolism( anus suppository 、、 pessary)pessary) ColoclysisColoclysis

Medicines causing Medicines causing the drug reactionthe drug reaction

Medicines causing Medicines causing the drug reactionthe drug reaction

50’s~60’s Sulfa-drugs Antipyretic

analgesic Antibiotic Hypnotics

80’s~90’s

•Antibiotic•Antipodagrics•Nonsteroidal antiinflammatatoyr agents•Sulfa-drugs

Skin testing is negtive, why does the drug still Skin testing is negtive, why does the drug still cause the reaction?cause the reaction?

The drug was discontinued a week ago, why The drug was discontinued a week ago, why do the eruptions appear now?do the eruptions appear now?

Penicilin did not cause reactions before, why Penicilin did not cause reactions before, why am I allergic to it now am I allergic to it now ？？

PathogensiPathogensiss

Why?Why?

Normal

human

A new drug

No eruptionNo eruption

4~20days 4~20days laterlater

eruptioneruption

No reactionNo reaction read

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istratio

read

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istratio

nn

Se

vere

eru

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eve

re e

rup

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within24hwithin24h

hypersensithypersensitivityivity

PathogenePathogenesissis

humanhuman

drugdrug

Special allergic reactionSpecial allergic reaction

AntigenicityAntigenicity

HypersensitivenessHypersensitiveness

????

Characteristic of Characteristic of allergic reactionallergic reaction

Has a certain Has a certain incubation periodincubation period Associated with humoral or cell-medAssociated with humoral or cell-med

iated immuneiated immune Readministration, eruption recur Readministration, eruption recur Cross-reactionCross-reaction Skin sensitivity test is positiveSkin sensitivity test is positive Indurate or desensitizeIndurate or desensitize Steroid and antihistamine are effectiSteroid and antihistamine are effecti

veve

Incubation periodIncubation period ：： from the day of contacting from the day of contacting antigen to that of eruption appearingantigen to that of eruption appearing

•First exposure to the medication : eruptions appear First exposure to the medication : eruptions appear an average of 7~9d (3~20days) after the drug i an average of 7~9d (3~20days) after the drug is starteds started

•ReadministrationReadministration ，， eruptions appear an average10eruptions appear an average10h( few minutes -24h) after the drug is startedh( few minutes -24h) after the drug is started

Clinical Clinical manifestatimanifestati

onon

Incubation periodIncubation period

The onset and The onset and evolution of the evolution of the eruptionseruptions

Clinical morphologyClinical morphology

CourseCourse

Different Different clinical clinical typestypes

Depended on

Two typical drug eruptionsTwo typical drug eruptions

（一）（一）

（二）（二）

VulgaryVulgary

Exfoliative dermatitisExfoliative dermatitis

Clinical feature of vulgClinical feature of vulgary drug eruptionary drug eruption

Incubation period ： 4~20days An acute onset of the disease Eruptions spread from face to tru

nk, extremities, and are symmetrical, general

Courses are 2~4 weeks, eruptions may clear if the medicine discontinues

Clinical morphology of vulgarClinical morphology of vulgary drug eruptiony drug eruption

Fixed eyrthema Toxic epidermal necrolysis Scarlatiniform eyrthema Morbilliform erythema Erythema multiform Urticaria Pityriasis rose Purpuric

Clinical feature of fixed Clinical feature of fixed erythemaerythema

Fixed One or several ， if recur ,eruption may be

increased, enlarged Favorite site at oral, genital mucosa Eruptions are round or elliptic prunosus

macule associated with edema Prolonged or permanent postinflammator

y hyperpigmentation

FixedFixed

erythemerythemaa

FixedFixed

erythemerythemaa

Fixed erythemaFixed erythema

Fixed erythemaFixed erythema

Morbilliform erythema

Morbilliform erythema

Urticaria Drug eru

ption

Pityriasis rosea drug eruptionPityriasis rosea drug eruption

Clinical feature of toxic epiderClinical feature of toxic epidermal necrolysis drug eruptionmal necrolysis drug eruption

Mucosal surface are erodedSevere constitutional symptoms are

often associated with high feverInternal organ involvementCoures: 3~4weeks

Lesions are macule or purpuric centers form bullae slough

Skin lesions rapidly spread

Epidermal necrolysis drug eruptionEpidermal necrolysis drug eruption

Epidermal necrolysis drug eruptionEpidermal necrolysis drug eruption

Erythema multiform drug eruptionErythema multiform drug eruption

Stevens-Johnson syndrome drug eruption

Clinical feature of exfClinical feature of exfoliative dematitis eruoliative dematitis eru

ptionption Has a long incubation period, often over

20days The symptoms are progressively severe The diffuse and generalized red macules

associated edema, scaly obviously Has constitutional symptoms Long course ， for 1~3months or longer

ExfoliativExfoliative dematitie dematitis eruptions eruption

DiagnoseDiagnose History of administration Incubation period Onset ： acute or progressively wo

rse Eruption ： morphology ， distribu

tion and number Have or no systemic symptom Course and prognosis Skin testing and reexposure test ：

cautiously evaluate

DiagnosDiagnosee

Drug eruption must be differentiated from

But sometime it is difficult to discriminateBut sometime it is difficult to discriminate

Infetious diseaseInfetious disease

Related dermatosesRelated dermatoses

DifferentiatedDifferentiated

from from

Morbilliform dMorbilliform d

rug eruptionrug eruption

Scarlatiniform Scarlatiniform

drug eruptiondrug eruption

DiagnoDiagnosese

MorbilliMorbilli

ScarlatinaScarlatina

Koplic maculeKoplic macule

StrawberrStrawberry tonguey tongue

Erythema Erythema multiformmultiform

Pityriasis rPityriasis roseaosea

UrticariaUrticaria

DiffereDifferentIatedntIated fromfrom

Erythema multifErythema multiform drug eruptiorm drug erupti

onon

Pityriasis rosea Pityriasis rosea drug eruptiondrug eruption

Urticarial drug eUrticarial drug eroptionroption

Differential Differential diagnosisdiagnosis

ProphylaxProphylaxisis

A detailed history from the patient Be familiar with the structure of dru

gs, prevent cross-react No drug abusing ， know of medica

tion indicatio Pay attention to the signs of porten

t reaction

TreatmentTreatment

Stop the suspected drugs immediately

General measure: keep warm, strengthen nutrition and egestion.

Drugs: anti-allergy, supportive treatment and prevent secondary infections

Drug Drug treatmenttreatment

Mild drug eruptione: antihistamine （may be various combinations ）， topical application of antipruritic powder or lotion

Moderately severe drug eruption ： steroid :prednisone ---dose:30~40mg/d, then reduce the dose according to the symptom

severe forms ： take measures as follows:

Treatment of Treatment of severe drug severe drug

eruptioneruption Corticosteroid ： intravenous use: hydrocortis

one 200-500mg/d Supportive treatment ： blood transfusion/ m

edium molecular dextran/ plasma adequate fluid intake

Prevent secondary infections: antibiotic treatment

Pay attention to the fluid and electrolyte balance, especially , especially to sylvite

Treatment to the internal involved Topical treatment

Topical treatmentTopical treatment ：：

skinskin

Powder \ lotion

compresses

acuteWithout oozing

oozing

subacuteWithout oozing

oozing

emulsion \ lotion

paste

mucous membrane strengthen nurse of mucous membrane strengthen nurse of cavity, prevent complicationcavity, prevent complication

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