Imported fire ant envenomation: A clinicopathologic study of a recognizable form of arthropod assault reaction. (21st September 2017)

• Record Type: Journal Article
• Authors: Villada, Gabriel; Hafeez, Farhaan; Ollague, Jose; Nousari, Carlos H.; Elgart, George W.
• Is Part Of: Journal of cutaneous pathology. Volume 44:Number 12(2017)
• Page Start: 1012
• Page End: 1017
• Publication Date: 2017-09-21
• Subjects: arthropod assault -- basophilic collagen degeneration -- imported fire ant -- subepidermal pustule; Skin -- Diseases -- Periodicals; Dermatology -- Periodicals; 616
• DOI: 10.1111/cup.13036
• Languages: English
• ISSNs: 0303-6987

Abstract

Abstract : 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.