Hives & Drug Induced Rashes Flashcards
Other name for Hives?
Urticaria
Classic presentation of Hives…?
-Elevated Welting
-Move & Change Shape
-Itchy
Viral URTI’s cause about ___% of hive rashes (espec. prevalent in kids).
40%
Food Allergies account for about __% of induced Hives cases.
1%
About ___% of Hives are caused by medications, & ______ are the most common culprit.
10% ; AB’s
_________ is an immunologic response to pressure applied to the skin.
Dermatographism
How long does Dermatographism last?
-Begins within 5mins & persists for 15-30mins.
DOC for Hive-Induced Itch?
2nd gen AH (reg. dose for few days - 2wks)
Topical Steroids good for Hives?
Sort of (playing catch-up due to transient nature of the Hives)
How does Contact or Allergic Dermatitis differ from Hives in presentation?
-Blistering (CD but none with Hives)
-Burning Skin (CD not with Hives)
-Hives can occur via multiple different mechanisms (substance ingestion / URTI / pressure).
Most common rash type from drugs?
Morbilliform Rash (appears Measle-Like)
Morbilliform Rash in kids is most often caused by what? In adults caused by what?
Kids: Viral Infection
Adults: Drug Induced
How does a drug-induced Morbilliform Rash present?
-1 to 2wks after starting drug
-Appears 1st on trunk, then spreads to limbs or neck
-Flat macules or papulas ; May be assoc. with mild fever or itch
Phototoxic Rxn’s?
-Resembles sunburn
-Fast OOA
-Typically clears up once drug d/c & cleared from body
Photoallergic Rxn’s?
-Resembles Eczema
-Generally Topical Drugs
Common drugs that may induce SJS?
-Sulfa AB’s
-Analgesics (Nap / Ace / Ibu)
-Gout Meds
-Seizure Meds
Most common symptoms of SJS?
Skin Pain accompanied by rash appearance after a few days
Is the appearance of a morbilliform rash within 3-14d of AB therapy enough to warrant a true drug allergy?
Nope… Rash will subside within 1-2wks of d/c therapy.
