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.

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.

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.

[Prevalence of hymenoptera sting allergy in veterinary medicine students from Monterey, Nuevo Leon, Mexico]

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.

Severe human urticaria produced by ant (Odontomachus bauri, Emery 1892) (Hymenoptera: Formicidae) venom

BACKGROUND

Ant sting reactions are becoming an increasing problem in tropical countries. It is important for physicians to be aware of their possible cutaneous and systemic manifestations.

METHODS

A child with a severe allergic reaction to an ant sting was examined and is discussed. This is the first case described in the literature caused by the ant Odontomachus bauri, and the biology of the ant and the clinical signs in the patient are described.

RESULTS

A child developed a strong allergic reaction to an ant sting. The case was not associated with a previous ant sting. Treatment with the systemic antihistamine loratadine (Clarityn) was favorable in this patient.

CONCLUSIONS

In tropical areas, ant stings are usually benign, self-limited pathologic processes. In some cases, however, severe allergic reactions can develop, including urticaria and anaphylactic shock. Physicians should be aware of the possible complications of ant stings.

Anaphylaxis due to Red Imported Fire Ant sting

The invasive Red Imported Fire Ant (Solenopsis invicta Buren) is well established at two locations in the Brisbane area, and we report a patient with anaphylaxis after a sting. The potential for anaphylactic events in Australia due to S. invicta will be greater than for native ants because of its unusual venom, its habit of forming supercolonies in grassy areas, and its aggressive group territorial defence, which can result in multiple stings.

Ant sting sporotrichosis

Cutaneous sporotrichosis is an uncommon infection, usually reported as sporadic cases resulting from inoculation with sharp environmental vegetative matter. We report such a case of multiple primary inoculations acquired from Solenopsis (fire ant) stings in a 54-year-old white man. The patient was treated effectively with itraconazole 200 mg twice a day for 4 months.

[Ant venoms: a rare cause of allergic reactions in Switzerland]

In Switzerland, unlike other countries, allergic reactions to ants are a rare phenomenon when compared to the well known allergies to bee and wasp venom. In this report we present a series of case reports and a review of the different types of allergy to ants. Due to increased travel and heterogeneity of the population, we have observed several patients with sensitisation or allergy to the venom of imported fire ants (Solenopsis), a species of ant found in the Americas. Furthermore, allergic reactions to bites of the mound-building wood ant (Formica rufa), whose habitat is Central and Northern Europe, have been documented. Whereas reactions to fire ants can be life-threatening, reactions to mound-building wood ants have led to marked local reactions and in 2 cases to dyspnoea and wheezing. These reactions could be due either to primary sensitisation to ant venom or cross-reactivity in the presence of an allergy to wasp venom. Evaluation of patients presenting with a potential ant venom allergy includes a detailed personal history, skin testing and determination of specific IgE. However, to date only extracts from fire ants are commercially available for diagnostic tests. In the light of our observations we assume cross-reactivity between the venoms of fire ants and mound-building wood ants, and it therefore seems appropriate to use fire ant diagnostics in determining sensitisation to mound-building wood ants. In patients with severe fire ant-venom allergy we recommend desensitisation by immunotherapy, whereas in patients presenting with minor allergic reactions, e.g. after bites by mound-building wood ants, we provide the patients with emergency medication. Since current knowledge of ant allergies in Europe is limited, further studies are warranted.

Fatal anaphylaxis due to fire ant stings

Imported fire ants (Solenopsis invicta and Solenopsis richteri) are the source of a potentially lethal environmental hazard in the southeastern United States. Because of their resistance to natural and chemical control, fire ants can overwhelm their environment, causing destruction of land and animals. Fire ants can also cause a variety of health problems in humans, ranging from simple stings to anaphylaxis and death. We present a case of a 30-year-old woman who died of anaphylaxis following multiple fire ant stings. At autopsy, multiple skin lesions characteristic of those produced by fire ant stings were present on her arm. Postmortem blood samples were positive for imported fire ant venom-specific IgE antibodies (5654 ng/ml) and tryptase (12 ng/ml). Deaths caused by imported fire ant stings are rare but are likely to become more common as the fire ant population expands. In this report, we review deaths due to fire ant stings, discuss postmortem laboratory findings, and stress the importance of recognizing the characteristic skin lesions produced by fire ants.

Hymenoptera hypersensitivity in an imported fire ant endemic area

BACKGROUND

Imported fire ants are a common cause of insect venom hypersensitivity in the Southeastern United States.

OBJECTIVE

The purpose of this study was to determine the most frequent insect cause for evaluation in a Hymenoptera hypersensitivity clinic in an area endemic for the imported fire ants.

METHODS

This was a retrospective study reviewing all patients seen in a venom clinic at a large teaching hospital.

RESULTS

Of the 703 patients evaluated, between 1985 and 1995, 515 (73%) had reactions consistent with systemic anaphylaxis for which a determination of specific IgE was appropriate. Of the 703 patients seen, 315 (45%) had a positive history and skin test positivity and were offered specific immunotherapy. This was 61% of those individuals skin tested. Of the total patients seen, imported fire ants were responsible for 42% of the visits to the clinic and accounted for 59% of the total immunotherapy that was begun in this endemic area.

CONCLUSION

In areas endemic for the imported fire ants, the most frequent cause of Hymenoptera hypersensitivity is the imported fire ant.

Safety and efficacy of fire ant venom in the diagnosis of fire ant allergy

Thirty-three adult patients who had had systemic allergic reactions to fire ant stings and 33 insect-nonallergic control subjects were skin tested with single lots of Solenopsis invicta (Sol i) fire ant venom (IFAV) and two commercially available imported fire ant whole body extracts (IFA WBEs). All three extracts were analyzed for protein concentration. Sol i II and Sol i III concentrations were each assayed by means of two ELISAs with complementary monoclonal antibodies, one species specific and one cross-reactive. Radioallergosorbent test (RAST) to IFAV and both IFA WBEs was performed on sera from all study subjects. Both IFA WBEs contained high concentrations of fire ant body proteins. Sol i II and III concentrations each varied twofold between the two IFA WBE preparations. Patients were generally more reactive to IFAV than IFA WBE by skin testing and RAST. IFAV RAST appeared to be a more sensitive assay than IFA WBE RAST. No adverse reactions occurred to skin testing with IFAV, but intradermal testing with higher concentrations of IFA WBE caused delayed large local reactions in 16 of 30 (53%) control subjects. These reactions were attributed to the large amounts of extraneous body proteins in IFA WBE. These results (1) demonstrate that skin testing with IFAV is safe, (2) indicate that IFAV is more potent than IFA WBE, and (3) suggest that IFAV may be the superior reagent for diagnosis of fire ant allergy.

Nephrotic syndrome associated with ant bite

A 3-year-old child experienced edema of the face and extremities approximately 2 weeks after being stung on the legs, scrotum, and penis by "fire ants" (Solenopsis invicta). After diagnosis of idiopathic minimal-change nephrotic syndrome and treatment with steroids, the edema rapidly disappeared. Follow-up 3 years after his hospitalization showed no recurrence of nephrotic syndrome. We have correlated this case with previously published reports of the causal relationship of allergy to nephrotic syndrome, but we are unaware of any previously published correlation between ant bite and nephrotic syndrome.

Multiple stings by imported fire ants (Solenopsis invicta), without systemic effects

This is the first case report of imported fire ants invading a building and aggressively attacking a human being, resulting in multiple stings. This case illustrates that, although the venom has a high LD50 in mice, it does not induce toxic systemic effects in humans when the venom is introduced intradermally.

The effects of a partially purified fraction of an ant venom in rheumatoid arthritis

A partially purified extract of an ant venom from the South American tree ant Pseudomyrmex sp. was tested in a double-blind, controlled study of patients with rheumatoid arthritis. Venom treated patients demonstrated an improvement in global efficacy and a decrease in the number of tender/painful joints and swollen joints. Swollen joint index improved in 60% of venom treated patients. Other parameters did not demonstrate significant change. Reduction of joint swelling was followed by symptomatic improvement that was sometimes delayed by weeks. Reactions were limited to erythema at the injection site (all patients), local pruritus (two-thirds of the patients), and fever with malaise (one-third of the patients). Further study of this venom in rheumatoid arthritis appears warranted in view of its apparent favorable efficacy-to-toxicity ratio.