Vitamin B12 (cobalamin) is a water-soluble vitamin that is derived from animal products such as red meat, dairy, and eggs. Cobalamin deficiency can be frequently seen in people all around the world. Desensitization is a treatment option if drug hypersensitivity develops and treatment is necessary. But intramuscular applications may cause treatment difficulties in such patients. A patient who developed cyanocobalamin deficiency due to pernicious anemia was shared. First, this patient was treated with cyanocobalamin. After treatment drug-induced hypersensitivity reaction developed. Desensitization was applied to the patient. Successful desensitization scheme was shared. Desensitization is of great value, as there are very limited treatment optıons in the literature on this subject, and it brings about a different option.
Alpha-gal allergy is the sensitization to Alpha-gal present in saliva when a tick bites and the development of an IgE-mediated reaction to Alpha-gal also present in red meat by cross-reactivity. In contrast to other food allergies, symptoms occur as late as 2-6 hours after a meal. Prick to prick testing with nonmammalian meat in combination with cooked mammalian meat is recommended for diagnosis. However, the main diagnostic test is Alpha-gal sIgE> 0.1 IU/mL. The primary recommendation in patients with Alpha-gal syndrome is to prevent new tick bites and avoid all mammalian meats. Since most of the dishes in our country's food culture contain red meat, elimination diet may adversely affect patients quality of life. In the management of these patients, the option of desensitization with red meat can be considered by evaluating the benefit-risk ratio together with the patient. Our patient with a history of tick bites and a reaction pattern ranging from urticaria to anaphylaxis two hours after meat consumption was evaluated for Alpha gal allergy. The patient was found to be positive by prick-to-prick with cooked red meat. In addition, the high level of Alpha-gal specific IgE (27.3 Ku/L) confirmed the Alpha-gal allergy, and the decision to apply desensitization with red meat was taken. There are only two literatures on this subject, one of which includes two adult cases and the other a single pediatric case. Since a reaction developed in the fifth step of the 27-step desensitization scheme (Ăśnal et al.), which we took as a reference, which led to a dose increase of more than 100 times, we modified the protocol by using an intermediate steps. We repeated the prick-to-prick test with red meat after desensitization in our case who successfully completed the modified desensitization protocol. Observation of more than half reduction in test edema diameter concretely supports the success of our modified desensitization protocol.
Keleş Ş, Gündüz M. Alpha gal specific IgE positivity due to tick bites and red meat allergy: the first case report in Turkey. Turk J Pediatr 2019; 61: 615-617. Galactose-alpha-1,3-galactose is a carbohydrate moiety found in the cell membranes of many organisms, commonly known as alpha-gal (α-Gal). This oligosaccharide is not found in the group of primates in which humans are involved. It has been found that α-Gal plays a key role in delayed IgE-mediated red meat allergy and this allergen is triggered by tick bites. Here we present a 7-year-old boy with alpha-gal allergy from Turkey.