Transcript 荨麻疹

Drug Eruption
Definition
Drug eruption : various kinds of drugs
delivered into human body by kinds of
means create the cutaneous and mucosal
reaction.
Drugs delivered by kinds of
means

Oral

Injections
(subcutaneous\intramuscularly\intravenous)

External use ( eye drops、nasal drops)

Inhalation

Buccal

Gargle

Embolism( anus suppository、pessary)

Coloclysis
Medicines causing the
drug reaction
50’s~60’s
 Sulfa-drugs
 Antipyretic
analgesic
 Antibiotic
 Hypnotics
80’s~90’s
•Antibiotic
•Antipodagrics
•Nonsteroidal
antiinflammatatoyr
agents
•Sulfa-drugs
Pathogensis
Skin testing is negtive, why does the drug still
cause the reaction?
Why?
The drug was discontinued a week ago, why
do the eruptions appear now?
Penicilin did not cause reactions before, why
am I allergic to it now ?
A new drug
Normal
No eruption
readministration
No reaction
hypersensiti
vity
4~20days
later
within24h
eruption
Severe eruption n
human
Pathogenesis
human
Hypersensitiveness
Special allergic??
reaction
drug
Antigenicity
Characteristic of allergic
reaction

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
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Has a certain incubation period
Associated with humoral or cellmediated immune
Readministration, eruption recur
Cross-reaction
Skin sensitivity test is positive
Indurate or desensitize
Steroid and antihistamine are
effective
Incubation period:from the day of contacting
antigen to that of eruption appearing
•First exposure to the medication : eruptions appear
an average of 7~9d (3~20days) after the drug is
started
•Readministration,eruptions appear an
average10h( few minutes -24h) after the drug is
started
Clinical
manifestation
Depended
on
Incubation period
The onset and evolution
of the eruptions
Clinical morphology
Course
Different
clinical
types
Two typical drug eruptions
(一)
Vulgary
(二) Exfoliative dermatitis
Clinical feature of
vulgary drug eruption

Incubation period:4~20days

An acute onset of the disease

Eruptions spread from face to
trunk,
extremities,
and
are
symmetrical, general

Courses are 2~4 weeks, eruptions
may clear if the medicine
discontinues
Clinical morphology of vulgary
drug eruption

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Fixed eyrthema
Toxic epidermal necrolysis
Scarlatiniform eyrthema
Morbilliform erythema
Erythema multiform
Urticaria
Pityriasis rose
Purpuric
Clinical feature of fixed
erythema

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 postinflammatory
hyperpigmentation
Fixed
erythema
Fixed
erythema
Fixed erythema
Fixed erythema
Morbilliform erythema
Morbilliform erythema
Urticaria
Drug
eruption
Pityriasis rosea drug eruption
Clinical feature of toxic
epidermal necrolysis drug
eruption
Skin lesions rapidly spread
Lesions are macule or purpuric
centers
form bullae
slough
Mucosal surface are eroded
Severe constitutional symptoms are
often associated with high fever
Internal organ involvement
Coures: 3~4weeks
Epidermal necrolysis drug eruption
Epidermal necrolysis drug eruption
Erythema multiform drug eruption
StevensJohnson
syndrome
drug
eruption
Clinical feature of
exfoliative dematitis
eruption

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
Exfoliative
dematitis
eruption
Diagnose
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History of administration
Incubation period
Onset:acute or progressively worse
Eruption:morphology,distribution
and number
Have or no systemic symptom
Course and prognosis
Skin testing and reexposure test :
cautiously evaluate
Diagnose
Drug eruption must be differentiated from
Infetious disease
Related dermatoses
But sometime it is difficult to discriminate
Diagnose
Morbilliform
Morbilli
drug eruption Differentiated
from
Scarlatiniform
drug eruption
Scarlatina
Koplic macule
Strawberry
tongue
Differential
diagnosis
Erythema
multiform drug
eruption
Pityriasis rosea
drug eruption
Urticarial drug
eroption
Differe
ntIated
from
Erythema
multiform
Pityriasis
rosea
Urticaria
Prophylaxis

A detailed history from the patient
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Be familiar with the structure of
drugs, prevent cross-react
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No drug abusing , know
medication indicatio
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Pay attention to the signs of portent
reaction
of
Treatment

Stop
the
immediately
suspected
drugs
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General measure: keep warm,
strengthen nutrition and egestion.

Drugs: anti-allergy, supportive
treatment and prevent secondary
infections
Drug treatment

Mild drug eruptione: antihistamine(
may be various combinations),topical
application of antipruritic powder or
lotion
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Moderately severe drug eruption:
steroid :prednisone ---dose:30~40mg/d,
then reduce the dose according to the
symptom
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severe forms:take measures as follows:
Treatment of severe
drug eruption
Corticosteroid:intravenous use: hydrocortisone
200-500mg/d
 Supportive treatment : blood transfusion/
medium 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 treatment:
skin
acute
Without
oozing
oozing
subacute
Without
oozing
Powder \ lotion
compresses
emulsion \
lotion
paste
oozing
mucous membrane strengthen nurse of cavity,
prevent complication
Thanks