Citation

Bernaba M, Power E, Campion J, Gotzen D, Schmidt JO, Klotz SA. Am. J. Med. 2019; ePub(ePub): ePub.

Affiliation

Department of Medicine, College of Medicine, Washington, DC. Electronic address: sklotz@u.arizona.edu.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.amjmed.2019.02.053

PMID

30953629

Abstract

A middle-aged female was taken from an abandoned automobile unconscious and covered with ants in Tucson, AZ. When hospitalized in July 2018 she had an extensive papular-pustular skin eruption on her abdomen and thigh and disseminated intravascular coagulation (DIC). She had been stung innumerable times by native golden fire ants (Solenopsis aurea) while sleeping in the vehicle. The clinical findings of fire ant stings are presented as well as the importance of recognizing the distinctive skin lesions produced by the stings. Stings of the red imported fire ant, Solenopsis invicta and the black imported fire ant, S. richteri, cause characteristic 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. Nevertheless, there is significant cross reactivity among the venoms of Solenopsis species. The large amount of venom injected by stings into this individual may have triggered DIC since the venom contains powerful hemolytic factors. Severe reactions caused by imported and native fire ant stings are infrequent, but are likely to become more common as fire ant populations expand. Case Presentation. A 52-year old woman was found unresponsive in an abandoned automobile and covered with ants. She had spilled pineapple cake in the car the day before. She was brought to the emergency room by ambulance. She had a past medical history of hepatitis C, cirrhosis, diabetes mellitus, intravenous drug abuse and chronic alcohol use. When last seen by a friend the evening before admission, she was feeling well. In the emergency department she was unconscious with a temperature of 102°F, pulse of 111 beats/min; a blood pressure of 71/44mmHg and a respiratory rate of 22 breathes/min. Her oral pharynx was normal; there was no wheezing on auscultation of the chest and no signs of bleeding; the fecal occult blood test was negative. There were small erythematous papules on her lower left abdomen and left upper thigh (Fig. 1). Initial laboratory results showed a hemoglobin of 3g/dL (normal 12.1-15.1/dL); platelet count of 47,000/mm³ (normal 150-450,000/mm³); elevated PT 33.7s (normal 11-13.5s), INR 2.94 (normal 0.8-1.1); APTT 44.5s (normal 30-40s), and a low fibrinogen of 95mg/dL (normal 150-400mg/dL). The total bilirubin was 7.7mg/dL (normal 0.1-1.2mg/dL) on admission and increased to 10.0mg/dL the following day. The direct bilirubin was 4.2mg/dL on admission (normal 0-0.4mg/dL). Haptoglobin was <10mg/dL (normal 30-200mg/dL) on admission. The fibrinogen degradation product titer was >20 (normal <5). LDH was 612IU/L (normal 40-330IU/L) and serum lactic acid was elevated at 2.36mmol/L (normal <2mmol/L). A peripheral smear showed significantly decreased platelets, moderate acanthocytes, burr cells and spherocytes. The laboratory results were interpreted as consistent with DIC. Alcohol and illicit drug screen of blood and urine respectively, were negative. The patient required norepinephrine intravenously to maintain blood pressure. She received intravenous fluids, packed red blood cells and became conscious. On the following day she required vasopressors again and the erythematous papules evolved into pustules (Fig. 1). She began oozing from all intravenous line sites and was treated with 2units of cryoprecipitate The pustules were biopsied and showed subcorneal and intradermal microabscesses, spongiosis and rare eosinophilic infiltrate with focal areas of leukocytoclasis consistent with envenomation effects from ant stings. The patient showed remarkable clinical improvement with resolution of shock and DIC and then expressed her wish to undergo no further escalation of care. The vehicle where the patient was found unconscious was visited and S. aurea was found feeding on pineapple cake on the trunk of the automobile (Fig. 2). Although the ant nest could not found it was likely under the abandoned vehicle and the ants were attracted by the spilled food.

Copyright © 2019. Published by Elsevier Inc.

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