Term
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Definition
Type 1: Histamine, IgE mediated, urticaria, angioedema
Type 2: cytotoxic, drug+Abs causes cell lysis
Type 3: serum sickness, drug induced vasculitis
Type 4: cell-mediated sensitization |
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Term
| exanthematous drug eruption |
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Definition
a cutaneous eruption that mimics the measles, morbilliform eruption (type IV)
most common
linked to PCN, allopurinol, gold salts
happens in almost 100% of patients with EBV of CMV given amp or amox, and 50-60% of HIV patients given sulfadrugs
sometimes a precusor to something more serious like SJS, TEN, hypersensitivity syndrome, or serum sickness |
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Term
uriticaria, angioedema, anaphylaxis
TX? |
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Definition
occurs 7-14 days after initial sensitization (the non-alleric type will occur 30 mins - 4 hours)
uriticaria - large wheals (lesions are usually white centered surrounded by red halo)
angioedema - large tissue swelling
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once the offending drug has been identified and discontinued, the symptoms can be treated using steroids
anaphylaxis may need epinephrine |
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Term
drug hypersensitivity syndome |
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Definition
occurs 2-6 weeks after drug is administered
rash, arthralgias, hematological maladies, lymphadenopathies
bright red lesions, systemic macules and papules
treat with oral histamines and topical or systemic steroids |
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Term
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Definition
an adverse cutaneous eruption that is localized in response to the ingestion of a drug
may be linked to OTC medications that a patient takes on a consistent basis
after the patient becomes sensitized, the lesion may occur mins to house after ingestion
the genital area is the most involved site
-demarcated round and oval, forms plaque, maybe a bullae, then an erosion |
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Term
| steven johnson syndrome and toxic epidermal necrolysis |
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Definition
mucocutaneous skin skin reaction patterns that ultimately lead to desquamation
-idiopathic
TEN is much more serious
SJS is considered a maximal manifestation of erythema multiforme
drugs implicated: sulfa drugs, allopurinol, aminopenicillins
1-3 weeks from drug use to onset
all blisters will have positive Nikolsky sign before the skin sloughs off. The key is the catch early because course is similar to thermal burns and TEN has a 30% mortality |
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Term
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Definition
3-5 days after anticoagulant therapy
manifested by sharply demarcated purpuric cutaneous infarctions
more common in women than men, and obesity increases risk greatly due to the abudance of subQ fat
may heal by granulation, but may also be life-threatening
administer vitamin K or protein C and treat necrotic skin as a 3rd degree burn |
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