Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 19 5 2020 10 18 550 554 EN Mohammad Nabavi Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Afshin Rezaeifar Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Ali Sadeghinia Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran Saba Arshi Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Sima Bahrami Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Mohammad Bemanian Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Morteza Fallahpour Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Sima Shokri Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran Zahra Vakilazad Department of Allergy and Clinical Immunology, Iran University of Medical Sciences, Tehran, Iran 2019 12 16 2020 09 07 Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease that may be triggered by some diseases and medications. For the latter one, non-steroidal anti-inflammatory drugs (NSAIDs) have been identified as one of the potential causative agents to develop LABD. Here, a rare case of drug-induced LABD is introduced. A 13-month-old Iranian boy presented with a history of generalized blisters, displaying the classic “string of pearls” sign who was eventually diagnosed as a case of LABD. In his admission, he was diagnosed whit Mucocutaneous lymph node syndrome and treated with aspirin.  Some features like appearing the characteristic lesions one week following the administration of aspirin, rapid clearance of lesions after the withdrawal of the drug, and reappearance of new lesions after readministration of aspirin were highly suggestive of aspirin-induced LABD. To establish the diagnosis, we used the “Naranjo probability score” which determined the probable causative role of aspirin. The diagnosis was confirmed by showing the positive IgA deposition in the basement membrane zone in a direct immunofluorescence study of the skin biopsy. The child was treated with dapsone with dramatical response to the drug. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/2641