Drug Eruptions Flashcards
presents within minutes to hours of ingestion; transient, pruritic erythematous edematous plaques anywhere on the body: wheals
Acute Urticaria
skin disorder due to mast cell degranulation and release of histamine
Acute Urticaria
tx for acute urticaria
Stop the offending medication, H1 antihistamines, +/- second-generation H1 antihistamines, +/- prednisone taper
Presents 7-14 days after initial medication exposure; likely due to drug or drug peptide hapten is presented by dendritic cells to T cells (cytotoxic); Type 4 hypersensitivity
Morbilliform drug eruption
Maculopapular rash- symmetrically distributed erythematous macules and papules on the trunk and upper extremities which then coalesce to become confluent
Morbilliform (Most Common)
TX for Morbilliform (Most Common)
Stop offending medication and will slowly resolve over 1-2 weeks; sometimes topical steroids for pruritus. (New lesions can appear even after stopping the meds b/c of gravity.)
Caused by aromatic anticonvulsants, sulfonamides, antiretrovirals, allopurinol; RegisSCAR scoring system is used to make a diagnosis; hypereosinophilia; Develops 2-6 weeks after drug exposure
DRESS
Rash has a morbilliform appearance but then becomes more edematous with follicular prominence on the face, upper trunk, extremities
Drug Reaction with Eosinophilia and systemic symptoms
Internal impact is involved (especially hepatic); any organ system can be affected; symptoms can last for weeks to months after medication withdrawal
DRESS
Diagnosis and TX for DRESS
Assessment/Diagosis:
- RegiSCAR scoring
- CBC w/diff (eosinophilia)
- peripheral blood smear (atypical lymphocytes)
- LFTs (hepatic dysfunction)
- BUN/creatinine (kidney dysfunction)
Tx:
- Systemic steroids
Time from exposure <4 days; commonly due to macrolides, beta-lactam antibiotics, and calcium channel blockers; high fever
Acute Generalized exanthematous pustulosis (AGEP)
Erythema starts on the face and in intertriginous areas then quickly spreads over a few hours; numerous non-follicular based sterile pustules
AGEP
Onset a few days to few weeks after initial exposure, subsequent exposure lesions appear at the same site
Fixed Drug Eruption
One or few rounds to oval sharply demarcated erythematous to dusky patches +/- bullae
Fixed Drug Eruption
Common causing agents/drugs of Fixed Drug Eruption
NSAIDs/acetaminophen/aspirin, sulfonamides, PPIs, tetracyclines
Epidermal detachment due to extensive keratinocyte death via apoptosis; Usual onset 7-21 days after medication exposure; Positive Nikolsky sign; Erythema and erosion of buccal, ocular, and genital mucosae present in > 90% SJS/TEN patients
Steven Johnson Syndrome/ Toxic Epidermal Necrolysis
Common causing agents of SJS/TEN
Sulfonamides (BACTRIM), anticonvulsants, NSAIDS, antiretrovirals, allopurinol
- same causing drugs as DRESS
What prodrome symptom precedes SJS/TEN?
upper respiratory tract symptoms
What drug eruption involves mucocutaneous symptoms?
SJS/TEN
Tx for SJS/TEN
stop offending drug; ICU/burn unit supportive care
what drug eruption has a high risk for infection, is hemodynamically unstable, and has impaired thermoregulation?
SJS/TEN
How long does re-epithelization take for SJS/TEN?
starts in days and usually complete in 3 weeks
