Angioedema after rt-PA infusion led to airway emergency: a case report of rescue treatment with fresh frozen plasma

Abstract The authors report the case of a 71-year-old woman presented to the Emergency Department with acute ischemic stroke. She was treated with rt-PA and interventional endovascular revascularization and developed rapidly progressing angioedema that led to emergency intubation. The standard treatment was not very effective and the swelling improved after infusion of fresh frozen plasma. Angioedema after rt-PA infusion could be a life-threatening emergency that requires quick airway management by skilled professionals. As this condition is triggered by several factors, such as unregulated histamine and bradykinin production, the traditional treatment recommended by the guidelines may not be sufficient and the use of FFP can be considered as a safe and valuable aid.

Histamine stimulates thermogenesis of brown and beige fat / 生理学报

β3-adrenergic agonists induce adaptive thermogenesis and promote beiging of white fat. However, it remains unclear which metabolites mediate the stimulatory effects of β3-adrenergic agonists on thermogenesis of brown and beige fat. In this study, adipose tissue was isolated from 8-week-old C57/BL6J male mice by intraperitoneal administration of β3-adrenergic agonist CL316,243 for RNA-Seq, which revealed that histidine decarboxylase, a key enzyme in histamine synthesis, was strongly induced in adipose by CL316,243. Therefore, we speculated that histamine might be involved in the process of thermogenesis in adipose tissue. We determined the physiological role and mechanism by which histamine promotes fat thermogenesis by intravenous administering histamine to C57BL/6J mice fed a normal or a high-fat diet. The results showed that intravenous injection of histamine into C57BL/6J mice fed a normal diet stimulated the expression of thermogenic genes, including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and uncoupling protein 1 (UCP1), in brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT). H&E staining also suggested that histamine treatment decreased the size of lipid droplets in adipocytes. Moreover, histamine treatment also enhanced thermogenesis of fat in high-fat diet induced obese mice, and improved glucose intolerance and fatty liver phenotype. Finally, we demonstrated that the effects of histamine on the thermogenic program were cell autonomous. Our data suggest that histamine may mediate the effects of β3-adrenergic agonists on thermogenesis of fat.

Intoxicación escombroide secundaria al consumo de atún: presentación de un caso / Scombroid poisoning secondary to tuna ingestion: a case report

Resumen: La intoxicación escombroide es ocasionada por el consumo de ciertos tipos de pescado (de la familia Scombridae), comúnmente el atún, los cuales acumulan grandes concentraciones de histamina cuando los procedimientos de refrigeración son inadecuados, ocasionando en quienes los consumen síntomas muy similares a los de una alergia alimentaria, por lo que es frecuente que no se diagnostique correctamente. Generalmente, los síntomas desaparecen en pocas horas y no suelen ser graves, excepto algunos casos descritos en la literatura especializada, de hipotensión, broncoespasmo, dificultad respiratoria, taquicardia supraventricular e, incluso, infarto agudo de miocardio. Este fue, precisamente, el caso de una mujer que ingresó al servicio de urgencias de un hospital de tercer nivel de Medellín a los pocos minutos de haber ingerido atún con una sintomatología típica de la intoxicación, pero con taquicardia supraventricular, una de sus manifestaciones graves y atípicas.

Abstract: Scombroid poisoning is caused by the consumption of certain types of fish (from the Scombridae family), especially tuna. Due to inadequate refrigeration procedures, these fish have high levels of histamine which generate symptoms similar to those of a food allergy in their consumers, so it is frequently underdiagnosed. It is self-limited in a few hours and the symptoms are usually not serious, except for specific cases reported in the literature of hypotension, bronchospasm, respiratory distress, tachyarrhythmias, and even acute myocardial infarction. We report here the case of a woman admitted to the emergency department of a third level hospital in Medellín a few minutes after eating tuna with the typical symptoms of intoxication, as well as tachyarrhythmias, a serious and atypical manifestation.

Individualized treatment for allergic rhinitis based on key nasal clinical manifestations combined with histamine and leukotriene D4 levels / Tratamento individualizado para a rinite alérgica baseado nas principais manifestações clínicas nasais e dos níveis de histamina e leucotrieno D4

Abstract Introduction The types of allergic rhinitis are roughly classified based on the causative antigens, disease types, predilection time, and symptom severity. Objective To examine the clinical typing and individualized treatment approach for allergic rhinitis and to determine the optimal treatment method for this disease using various drug combination therapies. Methods A total of 108 participants with allergic rhinitis were divided into three groups based on symptoms. Subsequently, each group was further categorized into four subgroups based on the medications received. The efficacy of the treatments was evaluated using the visual analog scale VAS scores of the total and individual nasal symptoms, decline index of the symptom score, histamine and leukotriene levels, and mRNA and protein expression levels of histamine 1 and cysteinyl leukotriene 1 receptors. Results Loratadine + mometasone furoate and loratadine + mometasone furoate + montelukast significantly improved the sneezing symptom and reduced the histamine levels compared with the other combination therapies (p < 0.05). Meanwhile, montelukast + mometasone furoate and montelukast + mometasone furoate + loratadine considerably improved the nasal obstruction symptom and decreased the leukotriene D4 levels compared with the other combination therapies (p < 0.05). Conclusion Clinical symptom evaluation combined with experimental detection of histamine and leukotriene levels can be an objective and accurate method to clinically classify the allergic rhinitis types. Furthermore, individualized treatment based on allergic rhinitis classification can result in a good treatment efficacy.

Resumo Introdução A rinite alérgica é basicamente classificada de acordo com os antígenos causadores, tipos de doença, peridiocidade e gravidade dos sintomas. Objetivo Avaliar os tipos clínicos e a abordagem terapêutica individualizada para cada tipo de rinite alérgica e determinar o método de tratamento ideal utilizando várias terapias de combinação de fármacos. Método Um total de 108 participantes com rinite alérgica foram divididos em três grupos com base nos sintomas. Posteriormente, cada grupo foi subsequentemente categorizado em quatro subgrupos com base nos medicamentos recebidos. A eficácia dos tratamentos foi avaliada utilizando os escores da escala visual analógica EVA dos sintomas nasais totais e individualmente, índice de declínio do escore de sintomas, níveis de histamina e leucotrienos e níveis de expressão de mRNA e proteína dos receptores de histamina 1 e cisteinil-leucotrieno 1. Resultados As associações entre loratadina + furoato de mometasona, assim como a de loratadina + furoato de mometasona + montelucaste melhoraram significativamente o sintoma de espirros e reduziram os níveis de histamina em comparação às outras terapias combinadas (p < 0,05). Por outro lado, a associação montelucaste + furoato de mometasona, assim como a associação montelucaste + furoato de mometasone + loratadina melhoraram consideravelmente o sintoma de obstrução nasal e diminuíram os níveis de leucotrieno D4 em comparação com as outras combinações (p < 0,05). Conclusão A avaliação clínica dos sintomas combinada com a detecção experimental dos níveis de histamina e leucotrieno pode ser um método objetivo e preciso para classificar clinicamente os tipos de rinite alérgica. Além disso, o tratamento individualizado baseado na classificação da rinite alérgica pode resultar no aumento da eficácia do tratamento.

Characteristics of Pruritus according to Morphological Phenotype of Psoriasis and Association with Neuropeptides and Interleukin-31

A case of nizatidine-induced immediate hypersensitivity

Nizatidine is a histamine H₂ receptor antagonist that inhibits stomach acid production and is commonly used in the treatment of peptic ulcer and gastroesophageal reflux. H₂ receptor antagonists are typically well tolerated, and hypersensitivity reactions are rare. A 19-year-old woman developed urticaria 30 minutes after taking a drug containing nizatidine. Allergic reactions to nizatidine were confirmed via skin prick test, which also revealed cross-reactions to ranitidine. We believe that this is the first case report on immediate hypersensitivity to nizatidine in Korea.

Síndrome de Kounis como manifestación de anafilaxia / Kounis Syndrome as a manifestation of anaphylaxis

Introducción: el síndrome de Kounis corresponde a la isquemia miocárdica aguda relacionada con la liberación de mediadores inflamatorios que llevan a vasoespasmo coronario y/o complicación de una placa ateromatosa durante una reacción alérgica. La incidencia de eventos coronarios en procesos alérgicos en Estados Unidos es de 8 casos por 100000 habitantes por año. Métodos: describimos el caso de una mujer que desarrolla síndrome de Kounis, posterior a múltiples picaduras de abeja, recibiendo manejo en una unidad de cuidado intensivo de una institución de salud de Colombia. La paciente presentó un síndrome coronario agudo tipo infarto agudo de miocardio con elevación del segmento ST, con arteriografía coronaria en la cual se evidenció ausencia de lesiones vasculares o vasoespasmo, con presencia de un trombo flotante en la arteria descendente anterior, sin evidencia de enfermedad ateroesclerótica. Resultados: el síndrome de Kounis es frecuente en los pacientes con anafilaxia, sin embargo, se informa poco en la literatura, debido a la falta de sospecha diagnostica y al poco reconocimiento clínico. Los síntomas de este síndrome pueden ser típicos como el dolor torácico opresivo de gran intensidad irradiado a miembro superior izquierdo o a cuello, o atípicos como disnea, nauseas o palpitaciones, los cuales pueden confundirse con las manifestaciones del proceso anafiláctico. Conclusiones: en la actualidad no existen guías para el tratamiento del síndrome y depende de la forma de presentación, comorbilidades y disponibilidad de un grupo médico interdisciplinar, que incluya monitoria y vigilancia en una unidad de cuidado intensivo.(AU)

Introduction: Kounis syndrome refers to the myocardial ischemia which results from the release of inflammatory-provoking mediators during an allergic reaction thereby causing coronary vasospasm and/or complication brought on by atheromatous plaque. The incidence of coronary disease induced by allergies in the United States is 8 cases per 100000 inhabitants per year. Methods: we cite the case of a woman who developed Kounis syndrome after receiving multiple bee stings. She was treated in the intensive care unit of a Colombian health institution. The patient presented with acute myocardial infarction with ST-segment elevation, and with no presence of vascular lesions or vasospasm during the coronary arteriography. It was further noted that there was a floating thrombus in the anterior descending artery without evidence of atherosclerotic disease. Results: Kounis syndrome is frequent in patients with anaphylaxis, however, only a few cases are reported in studies due to the lack of diagnostic suspicion and little clinical recognition. Symptoms suggesting this syndrome may be typical, such as oppressive chest pain which radiates to the upper left limb or neck, or atypical such as dyspnea, nausea, or palpitations which may be confused with the manifestations of the anaphylactic process. Conclusions: currently there are no directives for the treatment of the syndrome. It depends upon the manner of presentation, comorbidities, and the availability of an interdisciplinary medical group. It requires monitoring and surveillance in an intensive care unit.(AU)

Facilitation of spinal α-motoneuron excitability by histamine and the underlying ionic mechanisms / 生理学报

Spinal α-motoneurons directly innervate skeletal muscles and function as the final common path for movement and behavior. The processes that determine the excitability of motoneurons are critical for the execution of motor behavior. In fact, it has been noted that spinal motoneurons receive various neuromodulatory inputs, especially monoaminergic one. However, the roles of histamine and hypothalamic histaminergic innervation on spinal motoneurons and the underlying ionic mechanisms are still largely unknown. In the present study, by using the method of intracellular recording on rat spinal slices, we found that activation of either H or H receptor potentiated repetitive firing behavior and increased the excitability of spinal α-motoneurons. Both of blockage of K channels and activation of Na-Ca exchangers were involved in the H receptor-mediated excitation on spinal motoneurons, whereas the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels were responsible for the H receptor-mediated excitation. The results suggest that, through switching functional status of ion channels and exchangers coupled to histamine receptors, histamine effectively biases the excitability of the spinal α-motoneurons. In this way, the hypothalamospinal histaminergic innervation may directly modulate final motor outputs and actively regulate spinal motor reflexes and motor execution.

Establishment of new evaluation standards for systemic anaphylactoid reactions using mouse model / 中国中药杂志

The detection of drug-induced anaphylactoid reactions remains a global challenge,still lacking mature and reliable animal models or test methods. Therefore,the purpose of this paper is to explore and establish the test methods and evaluation standards for anaphylactoid reactions that apply to injection drugs. Based on the anaphylactoid reaction symptoms of mice induced by intravenous injection drugs C48/40 and Tween 80,a list of systemic anaphylactoid reaction symptoms in mice was sorted out and an evaluation standard of anaphylactoid reactions symptoms was established by applying symptom intensity coefficient K( that can represent these verity of anaphylactoid reaction symptoms) and its calculation formula Accordingly,histamine,tryptase,and Ig E were selected as blood indicators of anaphylactoid reactions,so that a test method combining symptoms evaluation and blood makers detection was established.This test method could be used to evaluate the characteristics of anaphylactoid reactions: coefficient K,blood histamine levels were highly and positively correlated with C48/80 and Tween 80 dose; The log value of histamine was highly and positively correlated with K; tryptase level may rise,or remain steady,or drop,possibly associated with the characteristics of the tested object and time for blood taking; and Ig E level would drop or remain steady,but it would not rise,which can be clearly distinguished from type I allergic reactions. On this basis,tiohexol,iopromide,paclitaxel,Xuesaitong Injection,Shuanghuanglian Injection and Shengmai Injection were used to investigate the applicability. The testing results showed a high degree of consistency with the actual clinical situation. The results suggest that the method of systemic anaphylaxis test in mice has high sensitivity,specificity and good consistency with clinical practice.It is suggested to be further validated and popularized.

Study on safflower yellow for injection based on cell degranulation and acute anaphylactoid model / 中国中药杂志

This paper was aimed to establish screening methods of anaphylactoid reaction caused by safflower yellow for injection based on RBL-2 H3 cell degranulation model and mice model for acute anaphylactoid reaction,and evaluate the hypersensitivity caused by safflower yellow for injection from different batches. An in vitro cell model was used to keep the cells stimulated for an hour with different batches of safflower yellow for injection as the drug group,serum-free MEM medium as negative control group and 30 mg·L-1 C48/80 as positive control group respectively. The supernatant was then absorbed,and neutral red staining technique was used to detect the effect of safflower yellow injection on the degranulation of RBL-2 H3 cells with the positive cell rate of degranulation as the indicator.An in vivo model was established to validate the experimental results,and mice model for acute anaphylactoid reaction and ELISA method were adopted to detect the plasma histamine content,and screen the hypersensitivity caused by safflower yellow for injection at the animal level by using plasma histamine content as a test index. The results of the neutral red staining experiments showed that the positive control C48/80 could cause cell degranulation,and most of the cells were deeply stained. There was significant difference in positive cell rate between different batches of safflower yellow and positive control group. In the mice model for acute anaphylactoid reaction,it was found that the positive control C48/80 significantly increased the histamine content in the plasma of mice,while the safflower yellow in each batch did not cause a significant increase in plasma histamine( P<0. 000 1). The mechanism of anaphylactoid reaction is relatively complicated. This study was mainly based on the release of histamine and other active substances by degranulation of mast cells. No significant degranulation reaction of RBL-2 H3 cells induced by safflower yellow for injection was detected,nor was the plasma histamine level significantly increased in mice from the in vitro and in vivo aspects.

Chronic Food Antigen-specific IgG-mediated Hypersensitivity Reaction as A Risk Factor for Adolescent Depressive Disorder / 基因组蛋白质组与生物信息学报·英文版

Major depressive disorder (MDD) is the most common nonfatal disease burden worldwide. Systemic chronic low-grade inflammation has been reported to be associated with MDD progression by affecting monoaminergic and glutamatergic neurotransmission. However, whether various proinflammatory cytokines are abnormally elevated before the first episode of depression is still largely unclear. Here, we evaluated 184 adolescent patients who were experiencing their first episode of depressive disorder, and the same number of healthy individuals was included as controls. We tested the serum levels of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), IgE, 14 different types of food antigen-specific IgG, histamine, homocysteine, S100 calcium-binding protein B, and diamine oxidase. We were not able to find any significant differences in the serum levels of hs-CRP or TNF-α between the two groups. However, the histamine level of the patients (12.35 μM) was significantly higher than that of the controls (9.73 μM, P < 0.001, Mann-Whitney U test). Moreover, significantly higher serum food antigen-specific IgG positive rates were also found in the patient group. Furthermore, over 80% of patients exhibited prolonged food intolerance with elevated levels of serum histamine, leading to hyperpermeability of the blood-brain barrier, which has previously been implicated in the pathogenesis of MDD. Hence, prolonged high levels of serum histamine could be a risk factor for depressive disorders, and antihistamine release might represent a novel therapeutic strategy for depression treatment.

Evaluation of symptoms and symptom combinations in histamine intolerance

BACKGROUND/AIMS: Food intolerance/malabsorption, particularly histamine intolerance (HIT), may cause nonspecific functional gastrointestinal and extraintestinal symptoms. We evaluated gastrointestinal and extraintestinal symptoms in patients with HIT. METHODS: In an analysis of outpatients' charts we identified 133 patients, who presented with recurring nonspecific functional gastrointestinal, extraintestinal symptoms, and a diamine oxidase value <10 U/mL, indicative of HIT. A standardized anonymous questionnaire with symptoms of HIT based on known symptoms and the 4 histamine receptors including gastrointestinal, cardiovascular, respiratory and skin complaints was developed, and sent by mail to the patients. RESULTS: In the 62 patients that completed the questionnaire, bloating was the most common and most serious symptom. Other commonly reported gastrointestinal symptoms were postprandial fullness, diarrhea, abdominal pain, and constipation. The presence of 2 from a list of 24 symptoms resulted in 276 various symptom combinations. From calculated 2.024 possible combinations of 3 symptoms the patients with HIT presented 1.975 combinations. CONCLUSIONS: The knowledge of this wide variability of symptoms and complex symptom combinations in patients with HIT may help to clinically recognize and diagnose HIT.

Dimerized, Not Monomeric, Translationally Controlled Tumor Protein Induces Basophil Activation and Mast Cell Degranulation in Chronic Urticaria

Translationally controlled tumor protein (TCTP) is also known as histamine releasing factor as it has the ability to activate mast cells. To investigate the role of TCTP in the pathogenesis of chronic spontaneous urticaria (CSU), we evaluated serum level of TCTP and effect of TCTP on basophil and mast cell degranulation. TCTP levels in the sera from 116 CSU patients and 70 normal healthy controls (NCs) were measured by ELISA. CD203c expression on basophils from CSU patients and β-hexosaminidase release from Laboratory of Allergic Disease 2 mast cells were measured upon stimulation monomeric and dimeric TCTP. Non-reducing Western blot analysis was used for detecting dimeric TCTP. No difference was observed in serum TCTP levels between CSU patients and NCs (p=0.676). However, dimeric TCTP intensity on Western blot was stronger in CSU patients than in NCs. TCTP levels were higher in patients with severe CSU (p=0.049) and with IgG positivity to FcɛRIα (p=0.038). A significant positive correlation was observed between TCTP and eosinophil cationic protein levels (Spearman's rho=0.341; p=0.001). Both basophil and mast cell degranulation were significantly increased after stimulation with dimeric TCTP, but not with monomic TCTP. The ability of TCTP to activate basophil and mast cells is dependent on dimerization, suggesting that the inhibition of TCTP dimerization can be a therapeutic option for CSU. Association between TCTP levels and the presence of IgG to high affinity Fc epsilon receptor I alpha subunit in CSU patients indicates that autoimmune mechanisms may be involved in the dimerization of TCTP.

Emerging Therapies in Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is characterized by typically short-lived and fleeting wheals, angioedema or both, which occur spontaneously and persist for longer than 6 weeks. This term is applied to the most common subtype of chronic urticaria. The underlying pathophysiology for CSU involves mast cell and basophil degranulation with release of histamine, leukotrienes, prostaglandins and other inflammatory mediators. Although a variety of treatments exist, many patients do not tolerate or benefit from the existing therapies and even require more effective treatments. Omalizumab is currently the only licensed biologic for antihistamine-refractory CSU, and novel drugs are under development. This article reviews its current status regarding pathogenesis and approach to treatment as well as therapeutic agents that are under development for the treatment of CSU.

Scombroid Fish Poisoning and Histamine Food Poisoning

Scombroid fish poisoning (SFP) is a form of histamine food poisoning caused by the ingestion of improperly stored fish. The term “scombroid” derives from the family name of the fish family first implicated, such as tuna and mackerel. On the other hand, non-scombroid fish species, such as sardine and herring, can also cause histamine poisoning. The histamine is converted from histidine by a bacterial enzyme in the causative fish. Because the symptoms of SFP can easily be confused with food allergies, it is believed to have been significantly under-reported. In 2016, an outbreak of SFP occurred among primary school students who had eaten yellowtail steak in Korea. The most common findings consisted of a rapid onset of flushing of the face and trunk, erythematous and urticarial rash, diarrhea, and headache occurring soon after consuming the spoiled fish. Usually, the course is self-limiting and antihistamines can be used successfully to relieve symptoms, but several life-threatening SFP cases have been reported. Clinical toxicologists should be familiar with SFP and have competency to make a differential diagnosis between fish allergy and histamine poisoning. SFP is a histamine-induced reaction caused by the ingestion of histamine-contaminated fish, whereas a fish allergy is an IgE-mediated reaction. This review discusses the epidemiology, pathophysiology, diagnosis, treatment, and preventive measures of SFP.

Antipsychotics for patients with pain

Going back to basics prior to mentioning the use of antipsychotics in patients with pain, the International Association for the Study of Pain (IASP) definition of pain can be summarized as an unpleasant experience, composed of sensory experience caused by actual tissue damage and/or emotional experience caused by potential tissue damage. Less used than antidepressants, antipsychotics have also been used for treating this unpleasant experience as adjuvant analgesics without sufficient evidence from research. Because recently developed atypical antipsychotics reduce the adverse reactions of extrapyramidal symptoms, such as acute dystonia, pseudo-parkinsonism, akathisia, and tardive dyskinesia caused by typical antipsychotics, they are expected to be used more frequently in various painful conditions, while increasing the risk of metabolic syndromes (weight gain, diabetes, and dyslipidemia). Various antipsychotics have different neurotransmitter receptor affinities for dopamine (D), 5-hydroxytryptamine (5-HT), adrenergic (α), histamine (H), and muscarinic (M) receptors. Atypical antipsychotics antagonize transient, weak D₂ receptor bindings with strong binding to the 5-HT(2A) receptor, while typical antipsychotics block long-lasting, tight D₂ receptor binding. On the contrary, antidepressants in the field of pain management also block the reuptake of similar receptors, mainly on the 5-HT and, next, on the norepinephrine, but rarely on the D receptors. Antipsychotics have been used for treating positive symptoms, such as delusion, hallucination, disorganized thought and behavior, perception disturbance, and inappropriate emotion, rather than the negative, cognitive, and affective symptoms of psychosis. Therefore, an antipsychotic may be prescribed in pain patients with positive symptoms of psychosis during or after controlling all sensory components.

Tradução e adaptação transcultural para o idioma português (Brasil) do instrumento "Angioedema Activity Score" / Translation and cross-cultural adaptation to the Portuguese language (Brazil) of the instrument "Angioedema Activity Score"

Introdução: Tradução e adaptação transcultural do instrumento Escore de Atividade do Angioedema (Angioedema Activity Score - AAS) para o idioma português do Brasil. Métodos: O documento original em alemão foi traduzido para o português (cultura brasileira) e posteriormente retrovertido para a língua alemã. As traduções foram analisadas pelos pesquisadores brasileiros e alemães para definição da versão final em português. A versão final foi respondida por 10 pacientes com angioedema recorrente, com o intuito de identificar possíveis dificuldades na compreensão e nos termos utilizados. Resultados: Todos os pacientes compreenderam as perguntas, embora apenas a metade tenha preenchido adequadamente o questionário. Conclusões: O documento do Escore de Atividade do Angioedema adaptado para a cultura brasileira se mostrou um instrumento fidedigno à versão alemã original.

Introduction: To translate and validate the Angioedema Activity Score to Brazilian Portuguese aiming further use of this tool in patients with recurrent angioedema. Methods: The original questionnaire in German was translated into Portuguese (Brazilian culture) and subsequently back translated into the German language. The translations were analyzed by Brazilian and German researchers to define the final version in Portuguese. The final version was administered to 10 patients with recurrent angioedema in order to identify possible issues in understanding the terms used. Results: All patients had a good comprehension of the questions, but only half of them completed the questionnaire properly. Conclusions: The Angioedema Activity Score adapted to the Brazilian culture proved to be a reliable instrument to the original German version.

Suppression of wheal and flare in histamine test by the main H1 antihistamines commercialized in Brazil

Abstract: Background: Several dermatoses are mediated by histamine, such as urticaria, angioedema, and papular urticaria. There are no Brazilian studies comparing the potency of antihistamines. Objectives: To evaluate the tolerability and efficacy of the main commercial brand and generic H1 antihistamines, regarding the suppression of the wheal and flare to the histamine test. Methods: A quasi-experimental, open study with 10 healthy adults submitted to the histamine test on the ventral aspect of the forearms. After 20 minutes, wheal and flares were measured. The tests were performed after two hours of intake of dexchlorpheniramine, hydroxyzine, levocetirizine, fexofenadine, cetirizine, loratadine, ebastine, desloratadine, epinastine and rupatadine, as well as generics of loratadine, cetirizine and fexofenadine. Results: All antihistamines presented a reduction in the wheal compared to the control (p <0.02), as well as in the flare, except for rupatadine (p = 0.70). In the internal comparison, cetirizine, fexofenadine, epinastine, levocetirizine, dexchlorpheniramine and hydroxyzine were the most potent, with no difference between them (p > 0.1). As for halo, cetirizine, epinastine, hydroxyzine and fexofenadine were the most potent, with no difference between them (p > 0.1). The most common adverse effect was drowsiness, which was more prevalent among first-generation drugs (p < 0.01). Generic loratadine, fexofenadine and cetirizine halos were higher than their controls (p <0.03).. Study limitations: A single-center study evaluating only aspects related to histamine. Conclusions: Brazilian commercial antihistamines presented different profiles of inhibition of wheal and flares in the histamine test, as well as adverse effects. Generic loratadine, fexofenadine and cetirizine presented larger flares than brand drugs.

Phloxine O, a Cosmetic Colorant, Suppresses the Expression of Thymic Stromal Lymphopoietin and Acute Dermatitis Symptoms in Mice

Cosmetics are primarily applied to the skin; therefore, the association of cosmetic dyes with skin diseases or inflammation is a topic of great interest. Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine that activates dendritic cells to promote Th2 inflammatory immune responses. TSLP is highly expressed in keratinocytes under inflammatory conditions, which suggests that it may play a critical role in the development of skin diseases, such as atopic dermatitis. Therefore, we investigated whether cosmetic dyes influenced the production of TSLP by keratinocytes. Phloxine O, also known as D&C Red No.27, is one of the most common red synthetic pigments and is widely used in colored cosmetics. Our results showed that Phloxine O downregulated phorbol 12-myristate 13-acetate-induced production of TSLP in a murine keratinocyte cell line (PAM212). Phloxine O also suppressed TSLP expression in KCMH-1 cells, which are mouse keratinocytes that constitutively produce high levels of TSLP. To investigate the in vivo effects of Phloxine O, we induced TSLP expression in mouse ear skin by topically applying MC903, a vitamin D3 analogue that is a well-known inducer of atopic dermatitis-like symptoms. Topical application of Phloxine O prevented MC903-induced TSLP production in mouse ear skin, attenuated the acute dermatitis-like symptoms and decreased serum IgE and histamine levels in mice. Suppression of TSLP expression by Phloxine O correlated with reduced expression of OX40 ligand and Th2 cytokines in mouse ear skin. Our results showed that Phloxine O may be beneficial to prevent dermatitis by suppressing the expression of TSLP and Th2 cytokines in skin.

Antipruritic effect of curcumin on histamine-induced itching in mice

Itching is a common clinical symptom of skin disease that significantly affects a patient's quality of life. Transient receptor potential vanilloid 1 (TRPV1) receptors of keratinocytes and peripheral nerve fibers in skin are involved in the regulation of itching as well as pain. In this study, we investigated whether curcumin, which acts on TRPV1 receptors, affects histamine-induced itching in mice, using behavioral tests and electrophysiological approaches. We found that histamine-induced itching was blocked by topical application of curcumin in a concentration-dependent manner. In ex-vivo recordings, histamine-induced discharges of peripheral nerves were reduced by the application of curcumin, indicating that curcumin acts directly on peripheral nerves. Additionally, curcumin blocked the histamine-induced inward current via activation of TRPV1 (curcumin IC₅₀=523 nM). However, it did not alter chloroquine-induced itching behavior in mice, which is associated with transient receptor potential ankyrin 1 (TRPA1). Taken together, our results suggest that histamine-induced itching can be blocked by topical application of curcumin through the inhibitory action of curcumin on TRPV1 receptors in peripheral nerves.