Peptide injections can sometimes cause redness or itching at the injection site, but most of the time this is not a true allergy. In the skin, we have mast cells that contain Frontiers Drug induced hypersensitivity syndrome related to piperacillin tazobactam: a case report and review of the literature Drug Allergy Allergy and Asthma Center of Duncanville Two novel cases of delayed drug rash after immune checkpoint inhibitors and platin combination treatment Annals of Allergy, Asthma & Immunology