A Sting, then Blisters and Pain

​A 25-year-old woman presented with a rash, and reported that she was in South Carolina when she felt a stinging sensation. That was followed by blisters on her foot.She noticed swelling of her foot, and had continued pain. She took pictures of the bite on days two and six. (Below.) She reported that she had a similar sting the previous summer. She said she had no fever, shortness of breath, or dizziness. Her vital signs were a temperature of 98.6°F, a heart rate of 80 bpm, a blood pressure of 100/60 mm Hg, a respiratory rate of 16 bpm, and an SPO2 of 100% on room air.She was alert and in no distress. Her oropharynx was clear without lesions or edema, and her lungs clear. Her left foot was swollen, with erythema and multiple pustular lesions. She reported no calf tenderness. Day Two.Day Six.The suspected culprit was the fire ant (Solenopsis invicta). These aggressive ants are found primarily in the southeastern United States. Fire ants lock their mandible on their victims and inject venom multiple times from a stinger.Local reactions are often painful and appear as a wheal, followed by sterile pustules, and then pustules with an umbilicated appearance on an erythematous base after 24 hours. Local edema occurs in large local reactions. Reported systemic reactions include anaphylaxis, DIC, rhabdomyolysis, renal failure, seizure, and bronchoconstriction.Fire ant venom are hypercoagulable, and contain multiple components that can inhibit Na+/K+/ATPase and uncouple oxidati...
Source: The Tox Cave - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs