Cutaneous Drug Reactions Flashcards
What is the most common type of cutaneous drug reaction and what does it look like?
Exanthematous drug eruption Widespread red macules and papules
Give some examples of drugs causing exanthematous drug eruptions?
Almost any drug e.g. penicillins, carbamazepine, allopurinol, NSAIDs
What is the timing of onset of drug induced urticaria?
Within 36 hours of taking the drug May be within minutes if given the drug again
Which drugs can cause an acute urticarial reaction?
Antibiotics e.g. penicillin NSAIDs ACE inhibitors
What does erythema multiforme look like?
TARGET lesions, vary in size May be mucosal involvement
What are some causes of erythema multiforme?
Idiopathic 50% Drugs e.g. sulphonamides, phenytoin, penicillin Infection –> HSV, mycoplasma
What are the features of Steven-Johnson syndrome?
Flu-like illness, fever –> then rash develops Mucosal erosions and epidermal detachment –> painful rash with blisters, top layer of skin dies and sheds Epidermal detachment < 10% total body surface
What is toxic epidermal necrolysis?
Similar to SJS but epidermal detachment > 30% High mortality due to sepsis
Which drugs can cause a vasculitis like reaction?
Allopurinol Amiodarone NSAIDs Thiazides Penicillin Sulphonamides Hydralazine
What is exfoliative dermatitis?
Drug induced erythroderma –> no skin left unaffected
Which drugs can cause exfoliative dermatitis?
Barbiturates Gold Quinine Sulphonamide
What is erythema nodosum?
Subcut swelling, tender red nodules on anterior shins
What are some causes of erythema nodosum?
Drugs e.g. OCP and sulphonamides Infections e.g. Strep, TB, Leprosy Sarcoidosis, IBD, Behcet’s syndrome
What is a fixed drug eruption?
Develops at the same site upon each exposure Itching/burning lesions Commonly on hands, feet, genitalia
What are some causes of fixed drug eruptions?
Tetracyclines NSAIDs Quinine OCP
