Reações alérgicas a ferroadas de insetos da classe Hymenoptera: uma revisão de literatura / Allergic reactions to hymenopteran stings: a literature review

Insetos como abelhas, vespas e formigas da ordem Hymenoptera podem causar reações alérgicas graves e até fatais. Esses insetos possuem venenos com componentes alergênicos e os injetam por meio de suas ferroadas, que podem causar reações locais e sistêmicas. O objetivo deste artigo é realizar uma revisão sistemática de literatura sobre as reações alérgicas às ferroadas de insetos da ordem Hymenoptera, com o intuito de analisar os mecanismos imunológicos envolvidos, as manifestações clínicas, os fatores de risco, os métodos de diagnóstico, as estratégias de prevenção e as opções terapêuticas disponíveis. Trata-se então de revisão sistemática de literatura realizada em agosto de 2023. O processo envolveu seis etapas. Os artigos foram obtidos pela busca em bases de dados, utilizando descritores em Ciências da Saúde relacionados ao tema. Foram identificados inicialmente 50 artigos, no entanto, apenas 10 deles atenderam aos critérios de inclusão. Para detecção das reações incluem-se testes cutâneos com venenos de Hymenoptera e análise do soro para IgE específica do veneno de Hymenoptera. Os fatores de risco que influenciam o resultado de uma reação anafilática incluem o intervalo de tempo entre as ferroadas, o número de ferroadas, a gravidade da reação anterior e o tipo de inseto. Esta revisão oferece uma visão abrangente das reações alérgicas às picadas de insetos Hymenoptera, contribuindo significativamente para o entendimento, diagnóstico e manejo dessas condições.

Insects of the order Hymenoptera such as bees, wasps, and ants can cause severe and even fatal allergic reactions. These insects have venom with allergenic components that they inject through their stingers, which can cause local and systemic reactions. This study aims to carry out a systematic literature review on allergic reactions to Hymenopteran stings, analyzing the immune mechanisms involved, clinical manifestations, risk factors, diagnostic methods, prevention strategies, and available therapeutic options. The literature review was conducted in August 2023, in a six-stage process. Articles were obtained by searching databases using Medical Subject Headings descriptors related to the topic. Initially, 50 articles were identified; however, only 10 of these met the inclusion criteria. We found that methods for detecting reactions include skin tests with Hymenopteran venoms and serum analysis for IgE specific to such venom. Risk factors that influence the outcome of anaphylactic reactions include the time interval between stings, the number of stings, the severity of the previous reaction, and the type of insect. This review provides a comprehensive overview of allergic reactions to Hymenopteran stings, contributing significantly to the understanding, diagnosis, and management of these conditions.

Discovery of an Insect Neuroactive Helix Ring Peptide from Ant Venom.

Ants are among the most abundant terrestrial invertebrate predators on Earth. To overwhelm their prey, they employ several remarkable behavioral, physiological, and biochemical innovations, including an effective paralytic venom. Ant venoms are thus cocktails of toxins finely tuned to disrupt the physiological systems of insect prey. They have received little attention yet hold great promise for the discovery of novel insecticidal molecules. To identify insect-neurotoxins from ant venoms, we screened the paralytic activity on blowflies of nine synthetic peptides previously characterized in the venom of Tetramorium bicarinatum. We selected peptide U11, a 34-amino acid peptide, for further insecticidal, structural, and pharmacological experiments. Insecticidal assays revealed that U11 is one of the most paralytic peptides ever reported from ant venoms against blowflies and is also capable of paralyzing honeybees. An NMR spectroscopy of U11 uncovered a unique scaffold, featuring a compact triangular ring helix structure stabilized by a single disulfide bond. Pharmacological assays using Drosophila S2 cells demonstrated that U11 is not cytotoxic, but suggest that it may modulate potassium conductance, which structural data seem to corroborate and will be confirmed in a future extended pharmacological investigation. The results described in this paper demonstrate that ant venom is a promising reservoir for the discovery of neuroactive insecticidal peptides.

Anaphylaxis reaction to Samsum ant (Pachycondyla sennaarensis): a case series study.

Summary: Background. Anaphylaxis is a life-threatening hypersensitivity reaction. The present study aimed to investigate the cases of anaphylaxis to ant stings in Iran to determine the characteristics of patients, geographical distribution and the type of ants that cause anaphylaxis. Methods. Patients with a history of anaphylaxis to ant sting underwent skin allergy test with extracted substance from Solenopsis invicta. Samples of ants were collected from the sites where each patient was bitten and their species were identified by a medical entomologist. Results. Nineteen patients (mean age: 26.2 years; range: 4-48 years) were included in the study. Most patients (89.5 percent) were female. The lower limb was the most common site of the sting and most stings had occurred in the morning (31.6 %) and evening (31.6%). Skin manifestations were the most common clinical symptoms (94.7%). Most cases of stings were observed in the Hormozgan province (89.5%) located in southern Iran. Sixteen patients had positive skin prick test for ant venom. All collected ants that caused anaphylaxis belonged to the Pachycondyla sennaarensis species. Conclusions. Ant sting anaphylaxis is not uncommon in Iran, especially in its southern regions. All cases of anaphylaxis in this study were due to samsum ant sting (Pachycondyla sennaarensis), which is a species similar to the fire ant (Solenopsis invicta). Allergy skin testing with fire ant extract was positive and helpful in identifying samsum ant allergy in all cases.

Unconscious Woman in Shock and Covered with Ants Pulled from an Abandoned Automobile.

BACKGROUND: A middle-aged woman was taken from an abandoned automobile unconscious and covered with ants in Tucson, Arizona. When hospitalized in July 2018, she had an extensive papular-pustular skin eruption on her abdomen and thigh and disseminated intravascular coagulation. She was stung innumerable times by native golden fire ants (Solenopsis aurea) while sleeping in the vehicle. The large amount of venom injected by stings into this individual may have triggered dissemnated intravascualar coagulation because the venom contains powerful hemolytic factors. METHODS: The patient history is presented and ants were captured and identified. RESULTS: Clinical findings of fire ant stings are presented and the importance of recognizing the distinctive skin lesions that occur is emphasized. Stings of the red imported fire ant, Solenopsis invicta, and the black imported fire ant, Solenopsis richteri, cause skin lesions recognized by physicians and victims alike in the southern and southeastern United States. Native fire ant stings are documented much less often. However, there is significant cross-reactivity among the venoms of Solenopsis species. CONCLUSION: It is important for clinicians to recognize the characteristic skin lesions of fire ant envenomation as fire ant populations are expanding and they sting millions of people each year.

Generalized papular-purpuric eruption due to Solenopsis fugax bites

Abstract: A 59-year-old atopic man referred to for the onset of a diffused itching papular-purpuric eruption involving his trunk and legs but without systemic symptoms. History revealed that he started feeling itching after spending few hours in his basement. Direct examination of the environmental dust (www.edpa.it) showed high level of infestation of Solenopsis fugax, a small Myrmicinae ant. The skin eruption completely healed without scarring in 2 weeks. Specific disinfestation measures were performed and the patient did not comply of any recurrence during a 6-months follow-up.

Anaphylaxis caused by stings from the Solenopsis invicta, lava-pés ant or red imported fi re ant

Ants are social insects with species of medical interest, such as the fi re ants (Solenopsis sp.). The sting causes inflammation, vesicles and sterile pustules, which may cause allergic phenomena and even anaphylactic shock. We describe a patient who suffered a large number of stings and an episode of syncope with fall in blood pressure and complete regression of symptoms after resuscitation and medication for anaphylaxis. Considering the clinical manifestations and images of wheals and blisters on the patient’s feet at the time of syncope, this report should serve as a warning for the diagnosis and treatment of this condition and even for counseling and prevention regarding patients exposed to this risk.

Venom toxicity and composition in three Pseudomyrmex ant species having different nesting modes.

We aimed to determine whether the nesting habits of ants have influenced their venom toxicity and composition. We focused on the genus Pseudomyrmex (Pseudomyrmecinae) comprising terrestrial and arboreal species, and, among the latter, plant-ants that are obligate inhabitants of myrmecophytes (i.e., plants sheltering ants in hollow structures). Contrary to our hypothesis, the venom of the ground-dwelling species, Pseudomyrmex termitarius, was as efficacious in paralyzing prey as the venoms of the arboreal and the plant-ant species, Pseudomyrmex penetrator and Pseudomyrmex gracilis. The lethal potency of P. termitarius venom was equipotent with that of P. gracilis whereas the venom of P. penetrator was less potent. The MALDI-TOF MS analysis of each HPLC fraction of the venoms showed that P. termitarius venom is composed of 87 linear peptides, while both P. gracilis and P. penetrator venoms (23 and 26 peptides, respectively) possess peptides with disulfide bonds. Furthermore, P. penetrator venom contains three hetero- and homodimeric peptides consisting of two short peptidic chains linked together by two interchain disulfide bonds. The large number of peptides in P. termitarius venom is likely related to the large diversity of potential prey plus the antibacterial peptides required for nesting in the ground. Whereas predation involves only the prey and predator, P. penetrator venom has evolved in an environment where trees, defoliating insects, browsing mammals and ants live in equilibrium, likely explaining the diversity of the peptide structures.