Background: Anaphylaxis is a constant perioperative concern due to the exposure to several agents capable of inducing hypersensitivity reactions. Patent blue V (PBV), also known as Sulfan Blue, a synthetic dye used in sentinel node research in breast surgery, is responsible for 0.6% of reported anaphylactic conditions. We present a case of a 49-year-old female patient who underwent left breast tumorectomy with sentinel lymph node staging using PBV and experienced an anaphylactic reaction. Methods: We conducted a literature search through PubMed for case reports, case series, reviews, and systematic reviews since 2005 with the keywords "anaphylaxis" and "patent blue". We then included articles found in these publications' reference sections. Results: We found 12 relevant publications regarding this topic. The main findings are summarized, with information regarding the clinical presentation, management, and investigation protocol. Hypotension is the most common clinical manifestation. The presentation is usually delayed when compared with anaphylaxis from other agents, and cutaneous manifestations are occasionally absent. Patients may have had previous exposure to the dye, used also as a food, clothes and drug colorant. Conclusion: The diagnosis of anaphylaxis in patients under sedation or general anesthesia may be difficult due to particularities of the perioperative context. According to the published literature, the presentation of the reaction is similar in most cases and a heightened clinical sense is key to address the situation appropriately. Finding the agent responsible for the allergic reaction is of paramount importance to prevent future episodes. (C) 2020 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda.

A anafilaxia pode ocorrer durante o período perioperatório devido à exposição a diversos agentes capazes de induzir reações de hipersensibilidade. O corante sintético Azul Patente V (APV), também conhecido como Sulfan Blue, é usado na pesquisa de linfonodo sentinela em cirurgia de mama, e é responsável por 0,6% dos eventos anafiláticos relatados. Descrevemos o caso de uma paciente de 49 anos de idade submetida à tumorectomia de mama esquerda com estadiamento de linfonodo sentinela, em que se empregou o APV e que apresentou reação anafilática. Por meio do PubMed, pesquisamos publicações que documentavam relatos de casos, séries de casos, revisões e revisões sistemáticas desde 2005, usando as palavras‐chave "anaphylaxis" e "patent blue". Em seguida, incluímos artigos encontrados na lista de referências dessas publicações. Encontramos 12 publicações relevantes sobre o tópico. Os principais achados estão resumidos, com informações do quadro clínico, tratamento e protocolo de investigação. A hipotensão foi a manifestação clínica mais frequente. De forma geral, o quadro clínico tem início tardio quando comparado à anafilaxia por outros agentes e, ocasionalmente, as manifestações cutâneas estão ausentes. Os pacientes podem ter tido exposição prévia ao APV, que também é usado como corante de alimentos, roupas e medicamentos. O diagnóstico de anafilaxia em pacientes sob sedação ou anestesia geral pode ser difícil devido às peculiaridades do contexto perioperatório. Segundo a literatura publicada, a apresentação da reação é semelhante na maioria dos casos e um discernimento clínico aguçado é fundamental para enfrentar o evento adequadamente. Encontrar o agente responsável pela reação alérgica é essencial para a prevenção de futuros episódios. Anaphylaxis is a constant perioperative concern due to the exposure to several agents capable of inducing hypersensitivity reactions. Patent blue V (PBV), also known as Sulfan Blue, a synthetic dye used in sentinel node research in breast surgery, is responsible for 0.6% of reported anaphylactic conditions. We present a case of a 49‐year‐old female patient who underwent left breast tumorectomy with sentinel lymph node staging using PBV and experienced an anaphylactic reaction. We conducted a literature search through PubMed for case reports, case series, reviews, and systematic reviews since 2005 with the keywords "anaphylaxis" and "patent blue". We then included articles found in these publications' reference sections. We found 12 relevant publications regarding this topic. The main findings are summarized, with information regarding the clinical presentation, management, and investigation protocol. Hypotension is the most common clinical manifestation. The presentation is usually delayed when compared with anaphylaxis from other agents, and cutaneous manifestations are occasionally absent. Patients may have had previous exposure to the dye, used also as a food, clothes and drug colorant. The diagnosis of anaphylaxis in patients under sedation or general anesthesia may be difficult due to particularities of the perioperative context. According to the published literature, the presentation of the reaction is similar in most cases and a heightened clinical sense is key to address the situation appropriately. Finding the agent responsible for the allergic reaction is of paramount importance to prevent future episodes.