After 8 to 10 hours, the fluid in the vesicle changes from clear to cloudy pustule, and the vesicle becomes umbilicated.. Edema, induration, and pruritus at the site occur in up to 50% o
Trang 1Clinical recognition The fire ant bites with well-developed jaws and then uses
its head as a pivot to inflict multiple stings There is immediate wheal and flare at the site The local reaction varies from 1 to 2 mm, up to 10 cm, depending on the amount of venom injected Within 4 hours, a superficial vesicle appears After 8
to 10 hours, the fluid in the vesicle changes from clear to cloudy (pustule), and the vesicle becomes umbilicated After 24 hours, the lesion is surrounded by a painful erythematous area that persists for 3 to 10 days Edema, induration, and pruritus at the site occur in up to 50% of patients Occasionally, systemic reactions occur as with other Hymenoptera
Management Treatment is symptomatic Local care includes ice and frequent
cleansing to prevent secondary infection Topical steroids, antibacterial medications, and antihistamines do not appear to prevent pustule formation Antihistamines are useful for pruritus Systemic reactions are rare and should be treated similarly to other Hymenoptera reactions
TERRESTRIAL VERTEBRATES
Venomous Reptiles
Goals of Emergency Care
Venomous substances are secreted by 15% of the United States’ 120 snake species An estimated 7,000 to 8,000 people are bitten annually by venomous snakes in the United States Emergency care is directed at providing timely antivenin therapy and expedient supportive medical care, which has dramatically reduced mortality and morbidity from poisonous snakebites Only 10 to 15 deaths are reported per year, but the morbidity in limb dysfunction and other complications is undoubtedly much higher With appropriate therapy, most long-term morbidity can be prevented
CLINICAL PEARLS AND PITFALLS
Identification of the snake may not be possible, but snakebite victims should be treated based on clinical symptoms
Extraction of venom is not usually helpful
Current Evidence
The pediatric population, especially males aged 5 to 19 years, accounts for a disproportionately large number of snake-bite victims The highest incidence