Urticaria and Angioedema Associated with Haloperidol

Sir, An 11-year-old girl presented in dermatology outdoor with facial edema, mainly affecting eyelids and lips [Figure 1], and widespread itchy urticarial lesions [Figure 2], accompanied with pain in the abdomen. There was no history of fever, chills, dizziness, and upper respiratory symptoms. She was a known case of type 1 diabetes mellitus and was regularly on insulin for the past 1 year. There was no history of any change in the medications for diabetes in the recent past. A detailed interrogation revealed that the child was started on haloperidol 2 days before developing skin lesions for irrelevant talks. She received tablet haloperidol 0.5 mg BD orally 3 doses. There was no history of any similar episode in the past. She was not known to be allergic to any medication in the past. There was no family history of angioedema. Her vitals were within normal limits. Systemic examination was normal. Further administration of haloperidol was stopped, and the patient was treated with oral antihistamines. The symptoms subsided within a day after 2 doses of chlorpheniramine maleate and cetirizine. After a few days, patient consumed haloperidol inadvertently and developed urticaria and angioedema again. She was treated again as before with improvement. The parents have been warned against the use of haloperidol. Haloperidol is an antipsychotic drug of the butyrophenone class. Haloperidol is widely used in the emergency department in a patient with agitation, mania, and psychosis.[1] It is known common adverse effects include extrapyramidal reactions, restlessness, neuroleptic malignant syndrome, dry mouth, tremor, and weight gain.[2] Haloperidol resembles droperidol derivatives pharmacologically.[3] Angioedema has been reported with several antipsychotics, including clozapine, risperidone, ziprasidone, droperidol, and chlorpromazine.[4] However, angioedema to haloperidol has only been reported rarely.[1,2,4] In one of these reports,[4] angioedema with haloperidol has occurred in association with iloperidol. We could not find any published report on haloperidol-induced urticaria in an extensive search of the English literature (PubMed, Google Scholar, Scopus, Medline, Embase, Index Medicus, Index Copernicus, etc.). However, urticaria as one of the adverse effect of haloperidol has been mentioned in Litt’s drug eruption and reaction manual.[5] The patient developed both urticaria and angioedema after taking 3 doses of haloperidol. Casuality assessment based on the Naranjo adverse reaction scale revealed a score of 5, suggesting a “Probable” association of angioedema and urticaria to haloperidol.