Drug eruptions Flashcards
What would a type I hypersensitivity reaction look like on the skin?
IgE mediated - urticaria
What would a type II hypersensitivity reaction look like on the skin?
Cytotoxic reaction - blistering rash
What would a type III hypersensitivity reaction look like on the skin?
Immune-complex mediated reactions - purpura and vasculitis
What would a type IV hypersensitivity reaction look like on the skin?
T cell mediated - macular/papular erythematous rash
What is an exanthematous drug eruption?
Type IV hypersensitivity - self limiting widespread rash with itch and mild fever
Which drugs can cause an exanthematous drug eruption?
Penicillins Erythromycin Allopurinol NSAIDs Chloramphenicol
What is an acneiform drug eruption?
Acne as a result of drugs but without whiteheads and increased sebum production
Which drugs can cause acneiform drug eruptions?
Glucocorticoids
What is a fixed drug reaction and which drugs can cause it?
A few painful, well demarcated lesions as a result of a reaction to:
tetracycline/doxycycline
paracetamol
NSAIDs
What is erythema multiforme?
Reactive disorder that is caused by infection or drugs
What are some infective causes of erythema multiforme?
Herpes Simplex Virus
Hepatitis B
Mycoplasma
EBV
What are some drugs that can cause erythema multiforme?
Thiazide diuretics
penicillins
Sulphonylureas
How does erythema multiforme typically present?
red target/bullseye lesions
What is a severe form of erythema multiforme?
Steven johnstone syndrome: sheets of annular lesions that can progress to toxic epidermal necrolysis (widespread burn)
Management of erythema multiforme?
Treat underlying cause
Supportive treatment
