ants and Exanthema

Imported fire ants aggressively sting humans, leading to a variety of local and systemic effects. Fire ants display a behavioral adaptation to survive flooding, called "rafting," bringing humans into even more contact with fire ants.. To assess frequency of encounters with fire ant rafts, duck hunters on the website "Duck Hunter's Forum" were asked about their experiences with the ants while wading or boating in flooded areas. All members of the group received a brief explanation and asked to respond directly if they had had such an encounter. They were then asked to fill out a short 6-question survey.. There were 2021 views of the thread about fire ant raft encounters, with 35 (1.7%) responses. Twenty-four (68.6%) said they had experienced encounters with fire ant rafts. Six responders described purposely or inadvertently physically touching the rafts with their body parts, boat, or a paddle, causing the ants to enter their boat or to climb directly onto the hunter(s). Five respondents were stung (number of stings from "a few" to 50), describing reactions to stings as "small pustules," "whelps," and "pimple-like, puss-filled whelps.". These results confirm that fire ant rafts formed during flooding present a potential hazard to persons walking, wading, or boating in those areas. We suggest that these rafts are an under-appreciated health hazard. It is reasonable to assume that people in flooded areas occasionally contact these floating rafts and are stung multiple times. We provide preliminary prevention/protection recommendations for health professionals, to be shared with their patients and the general public.

Topics: Animals; Ant Venoms; Ants; Exanthema; Floods; Humans; Insect Bites and Stings; Ships

Topics: Animals; Anti-Bacterial Agents; Ants; Exanthema; Female; Humans; Infant; Insect Bites and Stings; Rural Population; Skin; Sri Lanka; Treatment Outcome

Skin reactions to the sting of the imported fire ant have characteristic clinicopathological features.. 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.. 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.. 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.

Topics: Adult; Aged; Aged, 80 and over; Animals; Ant Venoms; Ants; Arthropods; Biopsy; Bites and Stings; Collagen; Dermis; Edema; Epidermis; Exanthema; Female; Humans; Inflammation; Male; Middle Aged; Neutrophils; Retrospective Studies; Skin Diseases; Violence