Background and objectives: Drug allergy is a major
problem frequently encountered. Patients are frequently
over diagnosed as having drug allergy without
proper confirmatory tests. The aims of this study were
to assess prevalence, clinical presentation and outcomes
among pediatric patients suspected of having
a drug allergy form medical history, and undergoing
drug allergy evaluation.
Methods: Medical records of pediatric patients who
had undergone evaluation for drug allergy in Ramathibodi
Hospital were reviewed. Patients were confirmed
to have a true drug allergy by a positive skin test and/
or drug provocation test.
Results: Sixty patients were evaluated for drug allergy.
Onset of symptoms was highly variable (median
4.5 hours; min-max 0.08-168). Skin and mucocutaneous
reactions were the most common presentations
(95%) particularly angioedema and urticaria (66.7%).
The most common suspected group of drugs was
antibiotics (71.7%), followed anti-pyretic/anti-inflammatory
(11.7%) and respiratory drugs (6.7%). Within
the group of antibiotics, Beta-lactam antibiotic was
the most common suspected drug causing allergy.
Only sixteen out of sixty patients (26.7%) were confirmed
to have a true drug allergy, 12 patients by skin test and 4 patients by drug provocation test. Drug
provocation test reactions did not correlate with
presenting symptoms of drug allergy. There were no
significant differences in age, onset or primary symptoms
of drug allergy between the confirmed true drug
allergy and no drug allergy groups.
Conclusions: Drug allergy is frequently reported, but
only a minority of patients have true drug allergy.
There were no precise clinical predictors for drug
allergy. Thus, drug provocation tests remain the gold
standard for diagnosis.
Keywords
drug allergy, drug provocation test, clinical presentation of drug allergy