Cutaneous Drug Eruptions Flashcards
how common are cutaneous drug eruptions
about 30% of adverse drug reactions are cutaneous
skin is very immunologically active
give an example of a type I(anaphylaxis) hypersensitivity drug reaction
urticaria
give an example of a type II(cytotoxic)hypersensitivity drug reaction
pemphigus and pemphigoid
give an example of a type III(Immune complex) hypersensitivity drug reaction
purpura/rash
give an example of a type IV(delayed) hypersensitivity reaction drug reaction
erythema/rash
what different morphologies can occur in cutaneous drug eruptions
exanthematous/morbilliform/maculopapular(75-95%), urticarial(5-10%), papulosquamous/pustular/bullous
who should be considered for cutaneous drug eruption diagnosis
any patient taking medication who suddenly develops symmetrical skin eruption
what are the risk factors for developing drug eruptions
age(mostly young adults), gender(F>M), genetics, concomitant disease, immune status(previous reaction)
what aspects of the drug are risk factors for drug eruptions
B lactam compounds, NSAIDs, dose, half-life
what is the most common type of drug eruption
exanthematous
what different presenting features are seen with cutaneous drug eruptions
pigmentation, itch, pain, photosensitivity, rash, erythema
what type of reaction is exanthematous drug eruption
idiosyncratic, T-cell mediated delayed type hypersensitivity (type IV)
what clinical features are associated with exanthematous drug eruptions
usually mild, self-limiting, widespread symmetrical rash, mucous membranes usually spared, itch common, mild fever common
what onset is usually seen in exanthematous drug eruptions
4-21 days after first taking drug
what are some indicators of potentially severe exanthematous drug reaction
facial erythema/oedema, fever, skin pain, blisters, purpura, necrosis, SOB, wheezing
