Drug Eruptions in Children: A Review of 111 Cases Seen in a Tertiary Skin Referral Centre

BP Khoo, YC Giam
Correspondence: A/Prof Y C Giam

ABSTRACT
A common dilemma faced by the clinician in the outpatient clinic is in distinguishing a drug eruption from a viral exanthem in a child. This is further confounded by multiple drugs frequently prescribed for common childhood ailment. Therefore many children are wrongly labelled as having drug allergy or mistakenly sent for allergy testing. This retrospective study seeks to address this common problem.
Method The case records of children aged 12 and below clinically diagnosed as having drug eruptions, seen from January 1995 to December 1997 in the National Skin Centre, were reviewed.
Results One hundred and eleven children were seen. The indications for drug prescribed were upper respiratory tract infection (47%), fever (18%) and chest infection (10%). The common discriminating drugs prescribed were amoxycillin/ampicill in in 59%, paracetamol in 36% and cotrimoxazole in 19% of patients. In general, the drug eruption took place within 1 day in 39%, by the 2nd day in 10% and by the 3rd to the 7th day in 13% of patients. Drug eruption patterns seen were urticaria/angioedema (45%), maculopapular rash (32%) and fixed drug eruption (12%). Drug allergy was confirmed in 8 patients (7%), while it was deemed probable in 22%, possible in 31% and unlikely in 41% of patients.
Conclusion A detailed drug history, knowledge of the various drug eruption patterns and drug specific reaction rates, and appropriate oral rechallenge test, are essential factors to the successful management of a child with drug eruption. Radioallergosorbent test (RAST) and patch test may be useful in some cases.

Keywords: children, drug history, drug eruption patterns, oral rechallenge, drug-specific reaction rates
Singapore Med J 2000; 41(11): 525-529