Ch 25 Drug Eruptions Flashcards
Causes of Drug Eruptions
- Pharmacology
- Allergy (1,2,3,4)
- Cummulative
- Altered skin ecology
- Overdose
- Idiosyncratic
- Exacerbation
Examples of non allegic
- MTX causing mouth ulcer
- Hydralazine, Minocycline causing lupus
- Dapsone/Rifampin causing reversal reactions in leoprosy
- Candidal Vaginitis with Abx
Cell types and reactions
CD4 tends to be morlbilliform
CD8 tends to be TEN and necrotisc
6 Questions to ask
- Can this be explained by a simple dermtosis
- Does rash suggest a drug eruption
- Past history of drug eruprtions
- Current drugs takin
- Recent changes in drugs
- Pattern of eruption with known drugs
Abx
- Mostly are toxic erythema but can cause a wide range
- Minocycline causes hyperpigmentation and can cause a lupus like syndrome
Penicillamine
-Most famous for pemphigus like with blood bullae
Gold
-Can cause anything
Anticonvulsants
-Most famous for SJS/TEN
Toxic Erythema
-Most common urticarial/morbilliform rash
Vasculitis
EN, PAN, etc
EM
Sulfa and anticonvulsants
Fixed Drug
- Purple papules that occur in the same place every time
- Penis
- Psychotropic, Abx, antifungals
Acneiform
-Li, Convulsants, TB
DRESS
Eosinophilia and internal organ involvment, significant rash and fever
-Fever with rash and drugs is always a bad sign
Photosensitivity
- Sulphur containing drugs
- thiazides, tetracyclines,
Psoriasis Drugs
B blockers, Li, Anticonvulsants
Fever
-Fever is always bad in drug eruptions and should prompt more serious look and treatment
