Drug Reactions

Question 1

What is a drug reaction?

Answer 1

An acute or subacute adverse cutaneous reaction to a drug or medicine

Question 2

Most common drug reactions?

Answer 2

Morbilliform or exanthematous drug eruption

Urticaria and/or angioedema (which rarely leads to anaphylaxis)

Question 3

What are severe cutaneous adverse reactions?

Answer 3

Can be life-threatening

Drug hypersensitivity syndrome

Stevens-Johnson syndrom/toxic epidermal necrolysis

Question 4

Clinical features of drug reactions

Answer 4

Fever

Malaise

Other organ involvement (in SCAR)

Urticaria

Angioedema

Pustolosis

Question 5

Investigations in drug reactions

Answer 5

History, skin and general physical exam

Determine exposure to medications under suspicion

Review medical record to determine relationship between onset of symptoms and commencing medications

FBC, LFTs, U+Es

Question 6

Management of drug reactions

Answer 6

Identify and stop responsible drug

Topical corticosteroids (e.g. betamethasone cream)

Emollients

Drug-induced urticaria often responds to antihistamines

Educate patient to avoid re-exposure an drugs with which it cross-reacts