Publication:

Etiology and immediate drug hypersensitivity in acute urticaria: a retrospective study

Background Acute urticaria is an immune mediated or non-immune reaction lasting for less than 6 weeks. This can be caused by food, drugs, infections, physical contact, insect bite but majority are reported to be idiopathic. Theoretically, almost any drug can cause urticaria especially antibiotics like penicillin. We carried out this study to assess the various etiologial factors and to assess the immediate hypersensitivity reaction to various drugs in acute urticaria.

Methods We reviewed the medical records of patients with acute urticaria in dermatology department from 2016 to 2018 (2 years) and recorded the demographic details, history of suspected cause, medications and intradermal drug test report in a standard proforma.

Results There were 154 cases of acute urticaria. Mean age of these cases were 36.48±11.37 years. 13.6% had associated angioedema. Mean duration of urticaria was 21.74±7.92 days. 40.9% cases were labelled idiopathic. Food accounted for 29.2% of the cases, drugs for 23.4% and infection for 5.2%. The rest 1.3% were due to insect bite. Intradermal drug test report showed the following frequency of positive reaction: diclofenac>ciprofloxacin= piroxicam>paracetamol=ketamine=diazepam>promethazine=atracurium.

Conclusions Most cases of acute urticaria were idiopathic whereas food, drugs, infections and insect bite were the specific causes. Fish among food, acetaminophen among drugs and streptococci among infections were most responsible agents. Immediate hypersensitivity to drugs in intradermal test were maximum for NSAIDs especially diclofenac and piroxicam followed by antibiotic namely ciprofloxacin in patients with acute urticaria.