Anaphylaxis and Severe Disseminated Intravascular Coagulation Due to Remdesivir.

A 69-year-old woman suffering with multiple myeloma developed coronavirus disease 2019 (COVID-19). Shortly after administration of remdesivir, she presented with symptoms of facial flushing, wheezing, and hypoxemia. Subsequently, thrombocytopenia and hypofibrinogenemia rapidly manifested, leading to a diagnosis of enhanced fibrinolytic-type disseminated intravascular coagulopathy (DIC). This clinical presentation was considered an immediate hypersensitivity reaction with associated coagulation abnormalities induced by remdesivir. Although remdesivir is generally considered safe and efficacious in the treatment of COVID-19, physicians should remain vigilant regarding the potential for severe adverse events associated with this medication.

Perioperative anaphylaxis management and testing: a quaternary centre audit.

BACKGROUND: Anaphylaxis is a severe, potentially life-threatening generalized or systemic hypersensitivity reaction. Sequential reports have cited anaphylaxis as the most common cause of anaesthesia-related deaths. We undertook an audit at a quaternary centre, examining the management of perioperative anaphylaxis and quality of referrals made to our anaesthesia allergy testing service. METHODS: The data of 41 patients consulted at St Vincent's Hospital Melbourne for perioperative anaphylaxis between 17th of January 2020 and 20th of January 2022 were analysed. Intervention outcomes included total intravenous fluid administered, adrenaline administration, instigation of CPR and the collection and the timing of serum tryptase samples. We also assessed referral quality, provision of institutional allergy alert and time elapsed from the anaphylaxis event to allergy testing. Contemporaneous Australian and New Zealand Anaesthetic Allergy Group (ANZAAG) guidelines were used as the reference standard for most outcomes. RESULTS: Our data reveals compliance of <80% with respect to intravenous fluid administration, referral quality and tryptase sampling, particularly at the 4-h timepoint. CONCLUSION: Surgical leadership and patient advocacy in the post-acute phase would likely facilitate requisite testing and improve the quality of counselling. We recommend institutions adopt a case-by-case review of management compliance with recommendations. Additionally, we advocate for the inclusion of a prompt to the ANZAAG referral form, that encourages the operator to update their patient's institutional allergy alert while awaiting allergy testing.

Venom Anaphylaxis: Decision Points for a More Aggressive Workup.

Diagnostic testing of patients who present for evaluation of insect venom allergy can involve many levels of investigation. A detailed initial history is critical for diagnosis and prognosis. The severity of previous sting reactions and the presence or absence of urticaria or hypotension predict severe future sting reactions and underlying mast cell disorders. Venom skin tests and specific IgE measurement can confirm the diagnosis but have limited positive predictive value for the frequency and severity of future sting reactions. Testing for serum IgE to recombinant venom component allergens can distinguish true allergy from cross-reactivity to honey bee and yellowjacket venoms. Basophil activation tests can improve the detection of venom allergy and predict the severity of reactions and the efficacy of venom immunotherapy but are limited in availability. An elevated basal serum tryptase level is an important marker for severe sting anaphylaxis and underlying mast cell disorders (eg, hereditary α-tryptasemia and clonal mast cell disease). When there is high suspicion (eg, using the Red Espanola de Mastocytosis score), bone marrow biopsy is the definitive tool to characterize mast cell disorders that are associated with the most severe outcomes in patients with insect sting allergy.

Pharmacist adjustment of preoperative antibiotic orders to the preferred preoperative antibiotic cefazolin for patients with penicillin allergy labeling.

PURPOSE: Emerging literature has detailed the safe use of cefazolin in patients with immunoglobulin E-mediated penicillin allergy labeling (PAL) such as hives and anaphylaxis. The purpose of this article is to detail efforts led by an antimicrobial stewardship pharmacist working with an interdisciplinary team to optimize preoperative antimicrobials in patients with PAL. METHODS: A pharmacist-led, interdisciplinary collaborative practice agreement (CPA) was activated in January 2020 to permit pharmacists to independently optimize preoperative antibiotics to the preferred cefazolin in patients with PAL if nonsevere or severe reactions had been reported. A patient registry was established covering the timeframe between January 8, 2020, and January 6, 2022. Reaction during surgery was assessed via 2-provider documentation, which included surgeon and anesthesiology staff documentation of any complications during the procedure related to a suspected allergic safety event. Utilization of cefazolin, clindamycin, and vancomycin for preoperative prophylaxis was monitored before and after implementation of the CPA. RESULTS: During the stated timeframe, 10,182 procedures and/or surgeries were completed on 1,572 (15.4%) patients with PAL and 659 (41.9%) patients previously reporting at least one reaction categorized as a severe reaction, which was hives for 71.2% of these patients. Of the 659 patients with PAL reporting a severe reaction, 356 received a preoperative cephalosporin (cefazolin, 98.8%; ceftriaxone, 1.2%) and tolerated it without a reported safety event, including 52 patients with PAL previously reporting anaphylaxis. An increase in preferred preoperative antimicrobial prophylaxis utilization was noted (cefazolin: 86% to 96.3%, P < 0.001; 2019 to 2021) with reductions noted in the use of nonpreferred preoperative antibiotics (clindamycin: 2.1% to 0.2%, P < 0.001; vancomycin: 3.2% to 0.4%, P < 0.001; 2019 to 2021). CONCLUSION: A pharmacist-led, interdisciplinary CPA increased preferred preoperative antimicrobial use in patients with PAL reporting severe allergic reactions, including hives and anaphylaxis, without reported safety events.

Cerebral venous thrombosis following an immunoglobulin-E mediated anaphylactic reaction.

BACKGROUND: Prothrombotic and pro-inflammatory states are known cerebral venous thrombosis risk factors. To date, two cases of venous thrombotic events after immunoglobulin-E mediated anaphylaxis have been reported. Herein, we describe the first case of cerebral venous thrombosis in close temporal relation with an immunoglobulin-E mediated anaphylactic event. CASE DESCRIPTION: A 51-year-old female presented with headache, language, and mental disturbance lasting for two days. Two days before the onset, she had undergone a provocative test with deflazacort to study an allergy history; after the test she developed a severe anaphylactic reaction. There were no other comorbidities, and in addition to contraceptive pill, she did not take other medications. On admission the patient was drowsy, with anomic aphasia, inattention and memory impairment. Magnetic Resonance Imaging depicted a left caudate and lenticulo-capsulo-thalamic venous infarct and thrombosis in the deep venous system. The patient was treated with anticoagulation and showed progressive improvement. Neoplastic and pro-thrombotic diseases were excluded. CONCLUSION: The close temporal association between the anaphylactic reaction and cerebral venous thrombosis suggests that anaphylactic reaction could have been a cerebral venous thrombosis precipitating factor. Immunoglobulin-E have been suggested to have prothrombotic activity by stimulating the release of platelet activation factor, thromboxane A2 and serotonin. This case adds on to the available information on possible cerebral venous thrombosis associated conditions.

A case series of perioperative anaphylaxis to cefazolin during kidney transplant and review of literature.

BACKGROUND: Intraoperative anaphylaxis is a life threatening and multiorgan system hypersensitivity reaction that frequently leads to cessation of operations. Despite the incidence of Cefazolin allergy being on the rise, the cases of anaphylaxis to Cefazolin during surgeries and its management are seldom reported. CASE PRESENTATION: We present two patients with no known beta-lactam allergy and end stage kidney disease who received perioperative intravenous Cefazolin for planned deceased kidney transplant surgery at our academic medical center. Both patients developed anaphylaxes approximately three minutes following the administration of the antibiotic and experienced severe, refractory hypotension that required the use of vasopressors. The severity of the anaphylactic reactions resulted in the cessation of the transplant operation and multiple days of intensive care unit admission. CONCLUSION: Peri-or intraoperative anaphylaxis to Cefazolin is on the rise and its consequences in transplant candidates are even more dire given the pre-existing end organ failure, financial burden for health care system, potential loss of donor organs, and emotional burden for recipients and their families. These are the first two cases of reported Cefazolin-induced anaphylaxis that actually resulted in aborting the kidney transplant operation. In addition, cases of previously reported Type 1 hypersensitivity to Cefazolin as prophylaxis for operations were reviewed and the allergy workups were discussed.

Hydatid Disease, an Uncommon Etiology of Death in Forensic Practice.

ABSTRACT: In Tunisia, hydatid cyst is an endemic parasitic disease. The cyst may remain asymptomatic, discovered accidentally, or in case of a complication, the most serious of which is sudden death. We propose, in this article, to analyze the degree of involvement of the cyst in the mechanism of death, through the review of 25 cases. A total of 7932 autopsy cases were performed during the study period. Twenty-five cases of hydatid cyst discovered at autopsy were collected and death was attributed to hydatid cyst in 13 cases. The seat of the cyst was variable and death was due to anaphylaxis in 10 cases, to hydatious embolism in 2 cases and to cardiac arrhythmia, resulting from a cardiac localization of a large hydatid cyst, in 1 case.Although rare, echinococcosis can be a life-threatening disease. Its involvement in the death mechanism remains difficult in many cases.

Tattoos Dermatological Complications: Analysis of 53 Cases from Northern Poland.

BACKGROUND: The frequency of tattoos varies from 10% to 30% across the population worldwide. The growing popularity of tattooing increases the number of cutaneous reactions connected with this procedure. As we have not found any previous studies in the literature concerning tattoo complications in Poland and other Eastern European countries, we believe this to be the first study of this kind. OBJECTIVE: The primary objective of this study was to evaluate the clinical spectrum of complications associated with the procedure of permanent tattooing among patients from Northern Poland. METHODS: Medical data of 53 patients who developed tattoo-related cutaneous conditions were analyzed. All of the patients were consulted in the Dermatology, Venereology and Allergology Clinic in Gdansk in the years 2018-2021. Medical history, dermatological assessment, and photographic documentation of skin lesions were performed in each case. Dermoscopic examination was carried out in 16 cases and 20 skin biopsies of the tattoo reactions were performed. RESULTS: Twenty-one patients (40%) presented tattoo ink hypersensitivity reactions, out of which 18 were triggered by the red ink. In 11 cases (21%), contact dermatitis has developed after tattooing, while 9 of the patients (17%) presented tattoo infectious complications, including local bacterial infections, common warts, molluscum contagiosum, and demodicosis. We collected 8 cases (15%) of papulonodular reactions in black tattoos, and in 6 of them, histology showed granuloma formation. In 2 cases (4%), symptoms of anaphylaxis were observed after the tattooing procedure, and in another 2 cases (4%), Koebner phenomenon in the tattoo was diagnosed. Dermoscopy was the clue to the diagnosis in 4 cases. CONCLUSIONS: This is the first report presenting multiple cases of tattoo complications from Eastern Europe. The results of the study are consistent with other researches, showing a similar distribution of tattoo complications and that across the different pigments used, the red ink is most frequently responsible for tattoo reactions. We emphasize the usefulness of dermoscopic examination in the diagnosis of tattoo-related infections and draw the reader's attention to the rare, yet hazardous complications connected with peri-tattooing anaphylaxis.

Influenza.

Seasonal influenza epidemics of variable severity pose challenges to public health. Annual vaccination is the primary way to prevent influenza, and a wide range of vaccines are available, including inactivated or live attenuated standard-dose, recombinant vaccines, as well as adjuvanted or high-dose vaccines for persons aged 65 years or older. Persons at increased risk for influenza complications include young children, persons with underlying medical conditions, and older adults. Prompt diagnosis of influenza can facilitate early initiation of antiviral treatment that provides the greatest clinical benefit. This article summarizes recommendations for providers on influenza vaccination, diagnostic testing, and antiviral treatment.

Anaphylaxis-related hemoperitoneum in 11 dogs.

OBJECTIVE: To describe the unique complication of hemoperitoneum associated with anaphylaxis. DESIGN: Retrospective case series from September 2012 to August 2017. SETTING: Two private emergency and specialty referral hospitals. ANIMALS: Eleven client-owned dogs diagnosed with anaphylaxis and hemoperitoneum upon presentation or referral. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Inclusion criteria included clinical signs consistent with anaphylaxis (hypotension, tachycardia, vomiting, diarrhea, weakness, collapse, with or without the presence of dermal signs) due to witnessed or unwitnessed presumed bee sting, an elevated alanine aminotransferase (ALT), performance of abdominal FAST (AFAST) examination with an abdominal fluid score, the sonographic presence of gallbladder wall edema, and hemoperitoneum. All dogs (n=11) were managed medically without surgical intervention. 91% (n=10) of dogs survived to discharge. CONCLUSIONS: Hemoperitoneum development can be seen with anaphylactic reactions, though the exact mechanism remains to be fully understood. Medical therapy is warranted and can be successful in these patients; surgery is not indicated to address hemoperitoneum.

[Patent blue V dye anaphylaxis: a case report and literature review]. / Anafilaxia por corante azul patente V: relato de caso e revisão da literatura.

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.

Patent blue V dye anaphylaxis: a case report and literature review / Anafilaxia por corante azul patente V: relato de caso e revisão da literatura

Abstract 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, review 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.

Resumo Introdução: 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. Método: 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. Resultados: 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. Conclusão: 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 induced bradycardia, renal failure, AV-nodal blockade, shock, and hyperkalemia: A-BRASH in the emergency department.

The emergency department (ED) is responsible for managing a variety of acute illnesses including undifferentiated shock. A newer less recognized syndrome termed BRASH - bradycardia, renal failure, AV-node blockers, shock and hyperkalemia - is a cycle of synergy between hyperkalemia and AV-blockade that can result in shock. This entity is more common amongst the elderly, considering polypharmacy and co-morbid diseases. Some cases have an inciting trigger of hypovolemia. Anaphylaxis is a potentially lethal form of shock that most emergency physicians (EP) treat in the ED. The two entities have never occurred simultaneously. Herein, we report a case of anaphylaxis induced BRASH syndrome occurring in an elderly diabetic man. The EP should be aware of this unique presentation of BRASH. It was concluded that the patient's anaphylaxis, caused hypovolemia, coupled with polypharmacy, and physiological stress, precipitated this severe form of shock and multi-organ system failure.

Anaphylaxis-induced atrial fibrillation and anesthesia: Pathophysiologic and therapeutic considerations.

Atrial fibrillation is the most common cardiac arrhythmia in western society affecting more than 35 million individuals worldwide annually. It is a common postoperative complication and may also occur spontaneously during general and local anesthesia administration. Aging, diabetes mellitus, hypertension, and cardiovascular diseases including cardiomyopathies, congenital cardiac anomalies, heart failure, myocardial ischemia, pericarditis, previous cardiac surgery, vascular disease, and valvular heart disease are some correlated factors. Beyond age, increased incidence of atrial fibrillation has been correlated to autoimmune system activation as it is the underlying mechanism of persistent atrial fibrillation development. Current research supports an association between the complement system activation and lymphocyte-pro-inflammatory cytokines release with the cardiac conduction system and atrial fibrosis. The loss of CD28 antigen from CD4+ CD28+ T lymphocytes seems to play a major role in atrial fibrillation development and prognosis. Except atrial fibrillation, a variety of additional electrocardiographic changes, resembling those with digitalis intoxication may accompany anaphylaxis and particularly Kounis syndrome. Histamine is one well-known mediator in allergic and inflammatory conditions as physiologically regulates several cardiovascular and endothelial functions with arrhythmogenic potential. The increased oxidative stress, measured by the redox potentials of glutathione, has been correlated with atrial fibrillation incidence and prevalence. The use of antazoline, a first-generation antihistamine agent used for rapid conversion of recent-onset atrial fibrillation in patients with preserved left ventricular function and for rapid atrial fibrillation termination during accessory pathway ablation denotes that anaphylaxis-induced histamine production could be the cause of atrial fibrillation at least in some instances. The anaphylaxis diagnosis in anesthesia can be challenging owing to the absence of cutaneous manifestetions such as flushing, urticaria, or angioedema. Anticoagulation for stroke prevention, rate and rhythm control medications, invasive methods such as radiofrequency ablation or cryoablation of pulmonary veins as well surgical ablation constitute the treatment basis of atrial fibrillation. Understanding the underlying mechanisms of atrial fibrillation by cardiologists, anesthesiologists and surgeons, as well as potential treatments, to optimize care is of paramount importance.

Hypovolemic shock after pelvic radiotherapy. A rare combination leading to a devastating complication.

BACKGROUND: Radiotherapy currently plays a key role in pelvic malignancies' management. Excellent outcomes have been reported on its association with chemotherapy for the treatment of the anal carcinoma. Despite that, the combined use of chemo- and radiotherapy and the high doses administered seem to be strongly associated with early and late onset side effects. METHODS: We reported a case of a 72 years old woman, affected by anal squamous cell carcinoma. She underwent chemotherapy, and then radiotherapy, with good results. RESULTS: During a regular MR control, the patient developed anaphylactic reaction to Gadolinium, and after that a rectosigmoid ischemia with total necrosis of the posterior rectal wall was diagnosed and surgically treated with Hartmann procedure. CONCLUSION: In our case we faced with the rapid and severe degeneration of pelvic anatomy determined by the sum of vascular alterations following hypovolemic shock and pelvic tissues alteration after radiotherapy. It seems essential not to underestimate the exponential outcome of a similar unusual combination of events. KEY WORDS: Anal carcinoma, Hypovolemic shock, Pelvic radiotherapy, Rectal necrosis.

Insect Sting Anaphylaxis-Or Mastocytosis-Or Something Else?

Insect sting anaphylaxis and mast cell disorders are intertwined in a specific and unusual way. There may be specific subsets of clonal mast cell disorders that are predisposed to sting anaphylaxis. The clinical characteristics of the sting reactions should raise suspicion of underlying mastocytosis (eg, hypotension without hives especially in a male). A baseline serum tryptase level is helpful in the evaluation of patients with insect sting anaphylaxis because it correlates with important risks for these patients, and they have a high frequency of abnormally elevated baseline levels. Elevated baseline serum tryptase level has been reported to correlate with clonal mast cell disease in patients with insect sting anaphylaxis but may also indicate one of several possible underlying syndromes, including mast cell activation syndrome (MCAS), familial hypertryptasemia, and idiopathic anaphylaxis. There is some overlap in these conditions, so it is important to evaluate the clinical pattern at presentation as well as laboratory markers, and to consider bone marrow biopsy to make a final and specific diagnosis of clonal mast cell disease. The presence of venom-IgE does not prove that the patient's previous sting reactions were IgE-mediated, but even low levels of venom-IgE in patients with mastocytosis predispose to severe sting anaphylaxis. Evaluation of all these possible factors will affect the recommendation for venom immunotherapy.

Massive release of the histamine-degrading enzyme diamine oxidase during severe anaphylaxis in mastocytosis patients.

BACKGROUND: Histaminolytic activity mediated by diamine oxidase (DAO) is present in plasma after induction of severe anaphylaxis in rats, guinea pigs, and rabbits. Heparin released during mast cell degranulation in the gastrointestinal tract might liberate DAO from heparin-sensitive storage sites. DAO release during anaphylaxis has not been demonstrated in humans. METHODS: Plasma DAO, tryptase, and histamine concentrations of four severe anaphylaxis events were determined at multiple serial time points in two patients with systemic mastocytosis. The histamine degradation rates were measured in anaphylaxis samples and in pregnancy sera and plasma with comparable DAO concentrations. RESULTS: Mean DAO (132 ng/mL) and tryptase (304 ng/mL) concentrations increased 187- and 4.0-fold, respectively, over baseline values (DAO 0.7 ng/mL, tryptase 76 ng/mL) during severe anaphylaxis. Under non-anaphylaxis conditions, DAO concentrations were not elevated in 29 mastocytosis patients compared to healthy volunteers and there was no correlation between DAO and tryptase levels in mastocytosis patients. The histamine degradation rate of DAO in plasma from mastocytosis patients during anaphylaxis is severely compromised compared to DAO from pregnancy samples. CONCLUSION: During severe anaphylaxis in mastocytosis patients, DAO is likely released from heparin-sensitive gastrointestinal storage sites. The measured concentrations can degrade histamine, but DAO activity is compromised compared to pregnancy samples. For accurate histamine measurements during anaphylaxis, DAO inhibition is essential to inhibit further histamine degradation after blood withdrawal. Determination of DAO antigen levels might be of clinical value to improve the diagnosis of mast cell activation.

Anaphylaxis-like reaction to anti-BRAF inhibitor dabrafenib confirmed by drug provocation test.

The combination of BRAF and MEK inhibitors is a standard therapeutic option for patients with metastatic melanoma with BRAF-mutated tumors. This type of targeted therapy improved patient survival, having a manageable toxicity profile. Nevertheless, potentially life-threatening severe toxicity as anaphylaxis-like reactions was observed in two reported cases. No confirmatory testing was performed for these two patients. We report a case of anaphylactic reaction to the BRAF inhibitor dabrafenib administered as a first-line treatment. The clinical picture is different compared with the reported cases, with the main life-threatening symptom being severe hypotension. An important feature of our case report is the diagnostic assessment by drug provocation test, which is considered the 'gold standard' investigation for the diagnosis of drug hypersensitivity. Additionally, serum tryptase levels were assessed, and the basophil activation test has been performed as an in-vitro diagnostic test. Elements in favor of both IgE-mediated and non-IgE-mediated reaction were observed, which is suggestive of a complex pathomechanism. This can be evocative for the heterogenous clinical manifestation of the immediate hypersensitivity reactions to BRAF inhibitors. The mechanisms responsible for the reactions should be investigated in future molecular and cellular studies.