eruption药物疹ppt课件.pptVIP

Drug Eruption ;What is drug eruption;Why do we have to know?;Why do we have to know?;Causes of drug eruption;Pathogenesis;Immunologic mechanism - unpredictable;Type I hypersensitivity (1);Type I hypersensitivity (2);Type II hypersensitivity (1);Red cells: Penicillin, chloropromazine, phenacetin Granulocytes: Quinidine, amidopyrine Platelets: sulphonamides, thiazides;Type II hypersensitivity (2);Type III hypersensitivity(1);Initially described following administration of therapeutic horse serum for treatment of pneumococcal pneumonia Now described following certain infections, administration of penicillin and other antibiotics, vaccines, and foreign proteins Onset usually at 7-10 days following injection, coincides with switch to IgG, onset at 1-3 days with subsequent exposures ;Characterized by fever, chills, skin rash;Type IV hypersensitivity;;Nonimmunologic mechanisms -sometimes predictable;Over dose Cumulative toxicity Drug-drug interactions Exacerbation of disease Pharmacological side effects ;Idiosyncratic with a possible immunologic mechanism-unpredictable ;DRESS TEN/SJS Drug reaction in the setting of HIV infection Drug induced lupus ;Clinical manifestation ;Most common form of adverse cutaneous eruption Lesions first appear proximally - especially groin and axilla, generalizing within 1-2 days Pruritus is usually prominent and is a distinguishing factor from a viral exanthem Tend to occur within the first two weeks of tx but may occur later, even up to 10 days after tx Most common cause: Antibiotics, especially semi-synthetic penicillin sulfamethoxazole/trimethoprim ;Differential diagnosis (DDx);Presentation: Wheals or angioedema. My be part of a more severe anaphylactic reactons with bronchospasm, laryngospasm, or hypotension Types: Nonimmunologic Aspirin and NSADS are the most common cause. They alter prostaglandin metabolism, enhancing degranulation of mast cells. Immunologic Most commonly associated with penicillin and related beta-lactam a