Successful desensitization with human insulin in a patient with an insulin allergy and hypersensitivity to protamine: a case report

<p>Abstract</p> <p>Introduction</p> <p>Insulin allergy may occur in patients treated with subcutaneous applications of insulin preparations. Besides additives in the insulin preparation such as protamine, cresol, and phenol, the insulin molecule itself may be the cause of the allergy. In the latter case, therapeutic options are rare.</p> <p>Case presentation</p> <p>A 68-year-old man with poorly controlled type 2 diabetes mellitus received different insulin preparations subcutaneously while on oral medication. Six to eight hours after each subcutaneous application, he developed pruritic plaques with a diameter of >15 cm at the injection sites that persisted for several days. Allergologic testing revealed positive reactions against every insulin preparation and against protamine. Investigation of serum samples demonstrated IgG antibodies against human and porcine insulin. We treated the patient with human insulin using an ultra-rush protocol beginning with 0.004 IU and a rapid augmentation in dose up to 5 IU. Therapy was accompanied by antihistamine therapy. Subsequent conversion to therapy with glargine insulin (6 IE twice daily) was well-tolerated.</p> <p>Conclusion</p> <p>As reported in this case, desensitization with subcutaneously administered human insulin using an ultra-rush protocol in patients with an insulin allergy may present an easy form of therapy that is successful within a few days.</p

Delayed-Type Heparin Allergy: Diagnostic Procedures and Treatment Alternatives-A Case Series Including 15 Patients

Delayed-type hypersensitivity reactions (DTHRs) after subcutaneous application of unfractionated heparins or low-molecular-weight heparins are not uncommon. Standard allergological testing usually includes intracutaneous skin tests and patch testing of different heparins, heparinoids, and thrombin inhibitors followed by subcutaneous and/or intravenous challenge with skin test-negative drugs. We present data from a single-center case series of 15 patients with DTHR after low-molecular-weight heparin administration. Intracutaneous testing that can be considered as gold standard identified the suspicious elicitor in 11 (73.4%) of 15 of the patients. Patch testing was positive in 5 (33.4%) of 15 of the patients and was only positive in patients who were also reacting in the intradermal testing. Intravenous challenge with heparin sodium was performed in 10 of 15 patients and was well tolerated in all cases, despite prior positive intracutaneous tests with the same substance. Intracutaneous documentation of DTHR was not an adequate predictor of intravenous challenge. Keywords: heparin, allergy, alternatives, pregnancy, cardiac surgery, thrombosi