Drug induced rashes Flashcards
What are examples of rashes induced by drugs?
Morbilliform, Hives, Photo-sensitive reactions, SJS/TEN
What is the most common form of drug eruption?
Morbilliform
What is morbilliform drug eruption
A measles like drug eruption due to drugs
Antibiotics are the most common group responsible for morb
90% of drug reactions
How to morbilliform eruptions look like
Measles/ Rash (exanthems) caused by viral or bacteria infections
MACULOPAPULAR
What is the cause of morbilliform skin rash in adults? Kids?
Adults usually due to drug
Kids are usually viral origin
What is the prevalence of morbilliform drug reactions?
2% of rx of new drugs cause a drug eruption and 95% of these cases are morbilliform
What are the clinical features of morbilliform drug eruption?
Usually appears 1-2 weeks after starting the drug, may occur up to 1 week after stopping drug
It is rare for a drug that has been taken for months or years to cause a morbilliform drug eruption
Appears in the trunk region and spreads to the limbs and the upper neck
Maculopapular
Rash may be associated with mild fever and itch (not infection, but actually drug rxn)
What is the treatment for a morbilliform drug eruption?
Stop taking the drug
Antihistamines (but not super helpful)
Wet wraps for red, inflammed skin
emollients and potent topical steroids
What are the common drugs responsible for morbilliform rashes?
penicillin
sulfa drugs
cephalosporins
anti-seizure drugs
allopurinol
What is the outlook for morbilliform drug eruption?
After the causative drug is ceased, the rash begins to improve within 48 hours and clears within 1-2 weeks
What to do if a pharmacist notices blisters or pus-filled morbilliform rashes?
Be worried and out of our scope, refer
What is the difference between a drug rash and hives?
Drug rashes have some itching or tenderness
Hives are super itchy!
What is the second most common type of drug rash?
Urticarial rashes or hives
Small pale red bumps that can form larger patches. V itchy
What are the common drugs for urticarial drug rashes?
NSAIDs
ACEi
Antibiotics –> penicillin
General anesthetics
What are the second most frequent cause of allergic drug reactions?
Antimicrobial sulfonamides
Less than 5%