Drug Eruptions Flashcards
What type of drug reaction occurs on the skin?
idiosyncratic drug reactions
Give an example of type 1, 2, 3 and 4 immunologically-mediated reactions?
1 = anaphylaxis 2 = Cytotoxic reactions 3 = immune complex delayed hypersensitivity reactions (purpura/rash) 4 = cell mediated delayed HR, T-cell mediated (erythema/rash)
Name two chemicals that can be involvedin drug eruptions
Beta-Lactam
NSAIDS
What is the most common type of drug eruption?
Exanthematous (90%)
What hypersensitivity reaction is involved in exanthematous drug eruptions?
Type 4
How long does a Exanthematous drug reaction usually take to occur?
4-21 days
What indicators are there of severe exanthmatous reactions?
Mucous membrane/face involvement, facial oedema & erythema, Widepsread confluent erythema, fever above 38.5, blisters, purpura, necrosis, lymphodenopathy, arthalgia, SoB and wheezing
Name some drugs involved in exathematous DE
penicillins, NSAIDs, erythro/stroptomycin, allopurinol, anti-epileptics, phenytoin, chloamphenicol, sulponamide antibiotics
Describe Urticarial DE
usually immediate IgE-mediated (type 1)
What causes inflammatory mediators from mast cells on 1st exposure in urticarial reactions?
Exposure to aspirin, opiates, NSAIDs, muscle relaxants, vancomycin, quinolones.
What causes an IgE-mediated type 1 Urticarial reaction?
rechallenge with drugs (B-Lactams antibiotics, carbazepine + many others)
What can cause Pustular or Bollous drug eruptions in a) Acne and b) Acute Generalised exanthematous pustulosus (AGEP)
a) glucocorticoids, androgens, lithium, isoniazide, phenytoin
b) antibiotics, calcium channel blockers, antimilarials
What drugs cause bollous pemphigoid?
ACEi, penicillin and furosemide
What drug can cause Linear IgA disease?
Vancomycin
Name two cutaneous adverse reaction
Stevens-Johnson Syndrome
Toxic epidermal necrolysis
