Comparison of Clinical Manifestations, Treatments, and Outcomes between Vespidae Sting and Formicidae Sting Patients in the Emergency Department in Taiwan.

BACKGROUND: Hymenopteran stings are the most common animal insult injury encountered in the emergency department. With increasing global spread of imported fire ants in recent decades, the rate of Formicidae assault has become a serious problem in many countries. Formicidae-associated injuries gradually increased in Taiwan in recent decades and became the second most common arthropod assault injury in our ED. The present study aimed at comparing the clinical characteristics of Formicidae sting patients with those of the most serious and common group, Vespidae sting patients, in an emergency department (ED) in Taiwan. METHODS: This retrospective study included patients who were admitted between 2015 to 2018 to the ED in a local teaching hospital in Taiwan after a Vespidae or Formicidae sting. Cases with anaphylactic reaction were further compared. RESULTS: We reviewed the records of 881 subjects (503 males, 378 females; mean age, 49.09 ± 17.62 years) who visited our emergency department due to Vespidae or Formicidae stings. A total of 538 (61.1%) were categorized into the Vespidae group, and 343 (38.9%) were sorted into the Formicidae group. The Formicidae group had a longer ED length of stay (79.15 ± 92.30 vs. 108.00 ± 96.50 min, p < 0.01), but the Vespidae group had more cases that required hospitalization (1.9% vs. 0.3%, p = 0.04). Antihistamines (76.8% vs. 80.2%, p < 0.01) were more frequently used in the Formicidae group, while analgesics were more frequently used in the Vespidae group (38.1% vs. 12.5%, p < 0.01). The Vespidae group had more local reactions, and the Formicidae group had more extreme, systemic, or anaphylactic allergic reactions. Creatine kinase was significantly higher in the Vespidae group with an anaphylactic reaction. Sting frequency in both groups exhibited the same positive associations with average temperature of the month and weekend days. CONCLUSION: Formicidae sting patients presented to the ED with higher rate allergic reactions and spent more time in the ED than Vespidae sting patients. However, Vespidae sting patients had more complications and higher rates of admission, especially with anaphylactic reaction. Laboratory data, especially creatine kinase data, were more valuable to check in Vespidae sting patients with an anaphylactic reaction in the ED. Both groups exhibited positive correlations with temperature and a higher rate on weekend days.

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.

Ant Bites Conjunctival Tissue: The ABCs of Removing an Ocular Ant Foreign Body.

BACKGROUND: A variety of insect-related ocular injuries have been reported in the literature. However, no reports have been published documenting injuries resulting from exposure of the ocular surface to ants. This is surprising, given the relatively ubiquitous presence of ants. This is the first known case report to describe various techniques utilized in the removal of ants from the ocular surface. CASE REPORT: This case report details the presentation of a distressed 24-year-old woman who presented to the Emergency Department with an ocular foreign body associated with pain and increased lacrimation. She was identified to have an ant adherent to her conjunctiva. Various techniques of removal were performed, with the ant finally removed without any trauma to underlying tissues. CONCLUSION: This is the first case report to detail various techniques utilized in the removal of ants from the ocular surface, and discusses salient features that treating physicians should be aware of in managing patients presenting with ant bites.

Safety of Repeated Imported Fire Ant Ultra-Rush Protocols.

Treatment of imported fire ant (IFA) hypersensitivity includes avoidance and venom immunotherapy (VIT) that reduces the risk of reactions to less than 5%. Previous studies have shown that rush immunotherapy (RIT) is safe and efficacious. It is unknown if multiple RIT procedures on individuals with breaks in VIT are safe and effective. This is a retrospective chart review of three patients who have undergone six IFA VIT rush protocols at our institution. Patients were all female with a median age of 27 years. All are active duty service members without medical problems who reside in an IFA endemic area. Reviewed protocols consisted of 10 injections of IFA whole body extract given in 1 day. Local reactions were the only side effect noted. All patients completed the protocols without further incident. Following each protocol, median VIT adherence was 9 months (range 2-72 months). Reasons for stopping VIT were deployment and pregnancy. Non-adherence is common and leads to breaks in VIT. The risk of VIT resumption in patients with previous RIT or VIT is unknown. This case series illustrates the safety and efficacy of repeated IFA VIT rush procedures in patients who for personal and service related reasons had breaks in VIT.

The allergic response mediated by fire ant venom proteins.

Fire ants are widely studied, invasive and venomous arthropod pests. There is significant biomedical interest in immunotherapy against fire ant stings. However, mainly due to practical reasons, the physiological effects of envenomation has remained poorly characterized. The present study takes advantage of a recently-described venom protein extract to delineate the immunological pathways underlying the allergic reaction to fire ant venom toxins. Mice were injected with controlled doses of venom protein extract. Following sensitization and a second exposure, a marked footpad swelling was observed. Based on eosinophil recruitment and production of Th2 cytokines, we hereby establish that fire ant proteins per se can lead to an allergic response, which casts a new light into the mechanism of action of these toxins.

Imported fire ant envenomation: A clinicopathologic study of a recognizable form of arthropod assault reaction.

BACKGROUND: Skin reactions to the sting of the imported fire ant have characteristic clinicopathological features. METHODS: One case of experimental envenomation was prospectively followed during 48 hours, with biopsies. In addition, 6 cases from our laboratory were retrospectively evaluated histopathologically for the following features: spongiosis, exocytosis (and type of cells), pustule formation, erosion/ulceration, epidermal necrosis, scale/crust, papillary dermal edema, inflammatory dermal infiltrate (cell type, density, depth, distribution, shape), red blood cell extravasation, vasculopathy and vasculitis. RESULTS: The typical lesion follows a very distinctive clinical and histopathologic evolution over 48 hours, with the formation of a subepidermal pustule overlying a wedge-shaped area of dermal collagen basophilic degeneration with scattered neutrophils. In the 6 cases retrieved from our files, the main features were a superficial and deep dermal, perivascular, periadnexal and interstitial infiltrate consisting of neutrophils, with basophilic degeneration of the collagen. A subepidermal pustule was noted in half of the cases. CONCLUSIONS: In biopsies taken in a clinical setting, even in the absence of the characteristic subepidermal pustule, the diagnosis of imported fire ant sting can be suspected if there is a superficial and deep perivascular, periadnexal and interstitial infiltrate composed of neutrophils, with some basophilic denaturation of collagen.

Pro- and Anticonvulsant Effects of the Ant Dinoponera quadriceps (Kempf) Venom in Mice.

Epilepsy affects at least 50 million people worldwide, and the available treatment is associated with various side effects. Approximately 20-30% of the patients develop seizures that persist despite careful monitored treatment with antiepileptic drugs. Thus, there is a clear need for the development of new antiepileptic drugs, and the venoms can be an excellent source of probes. In this context, while there are studies on venoms from snakes, scorpions, and spiders, little is known regarding venom from ants. The aim of this study was to investigate the potential pro- and anticonvulsant effects of the venom from the ant Dinoponera quadriceps (Kempf) in Swiss mice. After the injection of the crude venom (DqTx-5, 50, and 500 mg/mL) in the lateral ventricle of mice, we observed a reduction of exploration and grooming behaviors, as well as an increase in immobility duration. In addition, the crude venom induced procursive behavior and tonic-clonic seizures at the highest concentration. Conversely, the preadministration of the denatured venom (AbDq) at the concentration of 2 mg/mL protected the animals against tonic-clonic seizures (66.7%) and death (100%) induced by administration of bicuculline. Taken together, the findings demonstrate that D. quadriceps venom might be potential source of new pro- and anticonvulsants molecules.

Ant venom immunotherapy in Australia: the unmet need.

Jack jumper ant (JJA) venom allergy is an important cause of anaphylaxis in south-eastern Australia. The efficacy and real-world effectiveness of JJA venom immunotherapy (VIT) to prevent anaphylaxis in allergic patients are now well established, with an evidence base that is at least equivalent to that supporting VIT for allergy to other insect species. The tolerability and safety of JJA VIT are comparable with those of honeybee VIT.

A case of ant anaphylaxis.

A four-year-old girl developed anaphylaxis following ant stings at her parent's property in country New South Wales. The offending insect was identified by an entomologist as the green head ant. Ant sting anaphylactic reactions in Australia, the importance of identifying the offending insect following sting anaphylaxis and the signs of insect sting anaphylaxis are further discussed.

Ant venoms.

PURPOSE OF REVIEW: The review summarizes knowledge about ants that are known to sting humans and their venoms. RECENT FINDINGS: Fire ants and Chinese needle ants are showing additional spread of range. Fire ants are now important in much of Asia. Venom allergens have been characterized and studied for fire ants and jack jumper ants. The first studies of Pachycondyla venoms have been reported, and a major allergen is Pac c 3, related to Sol i 3 from fire ants. There are very limited data available for other ant groups. SUMMARY: Ants share some common proteins in venoms, but each group appears to have a number of possibly unique components. Further proteomic studies should expand and clarify our knowledge of these fascinating animals.

Imported fire ant immunotherapy prescribing patterns in a large health care system during a 17-year period.

BACKGROUND: No large evaluation has been performed of the maintenance vial concentration commonly used by physicians when prescribing imported fire ant (IFA) immunotherapy since the publication of the first Stinging Insect Hypersensitivity Practice Parameter 10 years ago. OBJECTIVE: To describe the prescribing patterns for IFA immunotherapy among practicing allergists in a large health care setting and the impact of published Practice Parameter recommendations. METHODS: Data from the US Army Centralized Allergen Extract Laboratory were analyzed to determine IFA immunotherapy prescribing patterns from 1990 to May 2007. This extract laboratory provides prescriptions for more than 320 US Department of Defense, US Department of Veterans Affairs, and US Public Health Service clinics. RESULTS: A total of 1,091 patients were given 1,437 new or revised prescriptions for IFA immunotherapy. Monotherapy for Solenopsis invicta and Solenopsis richteri was prescribed in 169 (11.8%) and 3 (0.1%) instances, respectively, with the remainder of patients given both IFA antigens. The most commonly prescribed maintenance vial dose was 0.5 mL of a 1:200 (wt/vol) dilution, accounting for 36.3% of prescriptions. A total of 17.3% of prescriptions had a maintenance vial dose of 0.5 mL of a 1:100 (wt/vol) dilution, 4.6% had a dilution of 1:10 (wt/vol), and 50.6% had a dilution between 1:10 and 1:100 (wt/vol). The mean starting dose was 4.4 10-fold dilutions below the maintenance dose (5.4 vials per treatment set). CONCLUSIONS: The most commonly prescribed maintenance dose was 0.5 mL of a 1:200 (wt/vol) dilution, although most prescriptions used a maintenance dose consistent with recommended dosing in the Stinging Insect Practice Parameters. Both IFA antigens were used by most physicians. Further study evaluating the effective dose range for IFA immunotherapy is needed.

The stinging impact of the imported fire ant.

PURPOSE OF REVIEW: Imported fire ants pose a real and present danger to allergic individuals living in endemic areas. This overview examines the impact of their presence, specifics of their venom and approach to the treatment of the hypersensitive individuals. RECENT FINDINGS: Imported fire ant sting attack rates are high in endemic areas with sensitization occurring early in life among those dwelling in these locations. Once considered an outdoor pest, sting attacks are now known to occur indoors with the very young and the very old being especially susceptible due to the decreased mobility of these age extremes. Immunotherapy with whole body extract appears efficacious with both traditional and rush schedules finding utility among allergists. Both the mobility of the populace and the portability of imported fire ants have broadened the presence of both allergic patients and the ant itself among allergists previously unfamiliar with hypersensitive patients or the imported fire ant. SUMMARY: Recent work has focused on achieving more rapid protection in hypersensitive patients given the high sting attack rates in endemic area with sensitization occurring early in life among those exposed to the imported fire ant.

[Prevalence of hymenoptera sting allergy in veterinary medicine students from Monterey, Nuevo Leon, Mexico]. / Prevalencia de la alergia a la picadura de himenópteros en estudiantes de medicina veterinaria de la ciudad de Monterrey, Nuevo león, México.

BACKGROUND: The reported prevalence of allergic systemic reactions to hymenoptera venom occur in up to 3.3% and large local reactions occur in 17% in the general population. OBJECTIVE: To investigate the prevalence of hymenoptera sting allergy in a group of veterinary medicine students from Monterrey, Nuevo Leon, Mexico. PARTICIPANTS AND METHODS: A transverse and observational study was done with 64 students of veterinary medicine. We conducted a questionnaire about the students' history of insect allergy and atopy. Skin test with allergenic extracts of bee and ant were practiced to all subjects. We performed aeroallergen skin prick test to the subjets with suspected atopy. RESULTS: Students age ranged from 17 to 25 years (mean 20.2) and 37 were males. Twenty students (31.3%) had clinical history of atopy and positive skin tests to aeroallergens. On the other hand, 5 students (7.8%), including 2 atopic, had suffered large local reactions, but none of them had suffered systemic reactions. Bee and ant skin tests were positive in 15.6% and 31.3% of the students respectively. There was no difference in the prevalence of hymenoptera allergy between atopic and non atopic subjects (p < 0.05). Further, the frequency of atopy in subjects with positive skin tests for bee and ant was 50%. CONCLUSION: The prevalence of large local reactions and hymenoptera sensitization found in this group was similar to that found in other epidemiologic studies.

Treatment of imported fire ant stings with mitigator sting and bite treatment--a randomized control study.

OBJECTIVE: To evaluate the efficacy of the commercially available product Mitigator Sting and Bite Treatment in reducing the pain after imported fire ant stings. METHODS: Twenty-four volunteer subjects were exposed to imported fire ant stings on both fore-arms. The subjects received Mitigator paste on 1 arm and calamine lotion on the opposite arm, in a blinded manner, from 90 seconds to 10 minutes after exposure. Subjects recorded pain on a 100-mm visual analog scale 60 seconds, 20 minutes, and 3 days after exposure. A 2-tailed paired t test was used to compare the difference in reduction of pain over time between the Mitigator-treated arms and the calamine-treated arms. RESULTS: At 60 seconds, the mean visual analog scale pain score was 23.9 mm for the Mitigator group and 24.5 mm for the calamine group. At 20 minutes, the mean score was 7.6 mm (delta = 16.3) for the Mitigator group and 12.7 mm (delta = 11.8) for the calamine group. At 3 days, the mean score was 2.4 mm (delta = 21.5) for the Mitigator group and 2.9 mm (delta = 21.6) for the calamine group. There was no significant difference between groups for change in visual analog scale pain score at 60 seconds, 20 minutes (P = .256), or 3 days (P = .64). CONCLUSIONS: There was no significant difference in pain relief between calamine and Mitigator for imported fire ant stings.

Natural history of large local and generalized cutaneous reactions to imported fire ant stings in children.

BACKGROUND: There are no published data on the natural history of large local and generalized cutaneous reactions to imported fire ant (IFA) stings in children. OBJECTIVE: To determine the natural history of large local and generalized cutaneous reactions to IFA stings in children not treated with immunotherapy by reviewing medical records from a venom clinic during the past 20 years. METHODS: Patients were selected for the study if they were 16 years or younger at the time of the reaction, had only cutaneous symptoms (generalized cutaneous or large local), and did not initiate immunotherapy. Each patient's parents were asked to recall whether the patient had experienced any further stings since the last evaluation at the venom clinic. RESULTS: We contacted 31 of 57 patients evaluated between July 10, 1984, and February 5, 2004. Twenty patients (65%) reported that they had not developed more severe reactions with subsequent stings. Reactions remained cutaneous only. Eleven patients (35%) had not been stung again since the original evaluation. Five of these patients had moved out of the IFA-endemic region. None of the previously evaluated patients reported subsequent life-threatening anaphylaxis from IFA stings. CONCLUSIONS: These limited data on IFA stings suggest a benign outcome in children 16 years and younger with large local or generalized cutaneous reactions. Larger and more extensive studies need to be conducted to further define the natural history of cutaneous reactions to IFA stings in children.