Drug allergy labels are prevalent among patients with hereditary angioedema but are frequently erroneous, often leading to delays in diagnosis and adverse clinical outcomes, according to the results of a new study published in Frontiers in Allergy.

The authors of the study, therefore, suggested that immunologists and allergists should review and investigate every suspicious drug allergy label, especially in patients with hereditary angioedema.

Hereditary angioedema attacks are often misdiagnosed as allergies, thereby increasing morbidity and mortality among patients. Misdiagnosed drug allergy labels can also lead to many adverse clinical outcomes.

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Here, a team of researchers from the Division of Rheumatology and Clinical Immunology, Department of Medicine at the University of Hong Kong led by Philip Hei Li, MBSS, MRes (Med), MRCP, collected and analyzed the clinical records of all patients with hereditary angioedema in Hong Kong. Of 41 patients with the condition, 9 (22%) had at least 1 drug allergy label on their medical records while 5 (56%) had more than 1 label.

Read more about hereditary angioedema attacks

The most common drug allergy label was to beta-lactams, which was seen in more than one-third of patients. 

The researchers found that the presence of a drug allergy label was associated with a delay in hereditary angioedema diagnosis, the likelihood of hereditary angioedema attacks, and the annual hospitalization rate. 

The researchers also conducted drug provocation tests on patients with hereditary angioedema who had drug allergy labels and disproved and removed them from the records.

Hereditary angioedema is a rare genetic disease characterized by repeated episodes of severe swelling, especially in the limbs, face, gastrointestinal tract, and airways. The condition is caused by a mutation in the SERPING1 gene, which leads to C1 inhibitor deficiency. The main function of C1 inhibitor is to inhibit the complement system and prevent its spontaneous activation.


Wong JCY, Cheong N, Lau CS, Li PH. Prevalence and impact of misdiagnosed drug allergy labels among patients with hereditary angioedema. Front Allergy. 2022;3:953117. doi:10.3389/falgy.2022.953117