Shigeno Ayami, Suzuki Tsuyoshi, Obayashi Masakazu, Asada Kei, Matsushima Satoru
Department of Emergency and Critical Care Medicine, Chutoen General Medical Center, 1-1 Shobugaike Kakegawa Shizuoka, Shizuoka, 436-8555, Japan.
Department of Dermatology and Skin Oncology, Chutoen General Medical Center, Shizuoka, Japan.
Int J Emerg Med. 2024 Mar 18;17(1):43. doi: 10.1186/s12245-024-00617-1.
We report a case of anaphylaxis induced by natto (fermented soybeans) allergy that occurred following dermal sensitization from a jellyfish sting.
A 49-year-old male presented to the emergency room complaining of an acute onset of erythema with pruritis that appeared while he was surfing. Given that his heart rate dropped to ~ 40 bpm without a decline in blood pressure or oxygen saturation, we suspected anaphylaxis and administered 0.5 mg of adrenaline intramuscularly. Immediately after the muscular adrenaline injection, his heart rate recovered to ~ 60-70 bpm.
The major allergen that induces natto allergy is poly(γ-glutamic acid) (PGA), which is present in its mucilage. Given that PGA is also produced by jellyfish tentacles, it can be inferred that the PGA sensitization occurred via dermal exposure to jellyfish PGA. This is an example of a food allergy induced by animal stings. As PGA is a high-molecular-weight polymer, natto allergy, despite being IgE-mediated, often presents with late-onset anaphylaxis, which typically develops half a day after digestion. PGA has a wide range of applications in pharmaceuticals, cosmetics, and foods. Patients may develop allergic symptoms and experience repeated anaphylaxis with no known cause. Therefore, it is important to obtain a detailed medical history and individually instruct patients suspected of being allergic to PGA to avoid PGA-containing products.
我们报告一例由纳豆（发酵大豆）过敏引起的过敏反应病例，该过敏反应发生在水母蜇伤导致皮肤致敏之后。
一名49岁男性因在冲浪时突然出现红斑伴瘙痒而就诊于急诊室。鉴于其心率降至约40次/分钟，而血压和血氧饱和度未下降，我们怀疑是过敏反应并肌肉注射了0.5毫克肾上腺素。肌肉注射肾上腺素后，他的心率立即恢复到约60 - 70次/分钟。
引发纳豆过敏的主要过敏原是聚（γ-谷氨酸）（PGA），它存在于纳豆的黏液中。鉴于水母触须也会产生PGA，可以推断PGA致敏是通过皮肤接触水母的PGA发生的。这是一例由动物蜇伤诱发的食物过敏。由于PGA是一种高分子量聚合物，纳豆过敏尽管由IgE介导，但常表现为迟发性过敏反应，通常在消化后半天发作。PGA在制药、化妆品和食品中有广泛应用。患者可能出现过敏症状并反复发生不明原因的过敏反应。因此，详细了解病史并针对疑似对PGA过敏的患者进行个体化指导以避免使用含PGA的产品非常重要。
