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 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 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 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 Be familiar with the structure of drugs, prevent cross-react No drug abusing ， know medication indicatio Pay attention to the signs of portent reaction of Treatment Stop the immediately suspected drugs 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 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 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