Caterpillar Envenomation Follow-up
- Author: Robert L Norris, MD; Chief Editor: Scott H Plantz, MD, FAAEM more...
Further Inpatient Care
- The vast majority of victims of erucism or lepidopterism are treated as outpatients. The rare patient with significant anaphylaxis following exposure should be admitted to the hospital for further standard monitoring and management.
- Victims of stings by the South American Lonomia caterpillars should be admitted to the hospital and observed for development of coagulopathy.
Further Outpatient Care
- Victims of caterpillar stings can be observed for 2 hours in the ED to ensure that they do not develop significant systemic toxicity.
- Although uncommon, secondary infection can occur following erucism or lepidopterism. Instruct patients to follow up immediately if any signs or symptoms of infection occur. Patients with particularly severe exposures should have scheduled follow-up care to exclude infection or necrosis.
- All patients with ocular exposures to caterpillar or moth hairs or setae should receive early ophthalmologic follow-up care to exclude retained fragments, which can lead to catastrophic complications.
- Following caterpillar stings, local findings, including pain, may persist for several days. Systemic symptoms usually resolve in 24 hours.
- Patients who experience a significant allergic reaction to caterpillar exposure (eg, hypotension, bronchospasm) should receive a prescription for an epinephrine self-administration device prior to discharge from the hospital and should be instructed in its use. They also should consider obtaining and carrying medical alert identification of this history. Unlike therapy for hymenoptera-induced anaphylaxis, there is no desensitization therapy for patients highly allergic to caterpillars.
Deterrence/Prevention
- All caterpillars should be considered potentially toxic, and contact should be avoided. Children particularly should be warned in this regard. When working outdoors during peak caterpillar seasons, individuals should wear long-sleeved shirts, long pants with the cuffs tucked into their socks, and work gloves. Collars should be close fitting to avoid having a caterpillar fall into one's shirt. When working in an area where airborne caterpillar debris is a problem, a tight-fitting face mask and eye protection should be used. Laundered clothing should not be hung outdoors to dry as it may collect airborne caterpillar debris.
- Insecticides can be used to control caterpillar populations. A professional pest specialist or entomologist should be consulted before applying such agents because many caterpillar species are beneficial to agricultural and ornamental plants.
- If a caterpillar is found on one's body, it should be gently lifted off with a stick to avoid contact with potentially toxic hairs, setae, or hemolymph.
Complications
- The wounds or dermatitis that follow exposures to irritant or toxic caterpillars and moths can become secondarily infected, which can lead to scarring and permanent dysfunction. The risk is increased when hairs or spines are retained or in patients with severe pruritus that leads to excessive scratching. In rare cases, necrosis can result from prolonged exposure to caterpillar or moth setae.
- Ocular exposures can cause development of keratitis, acute uveitis, retinochoroiditis, endophthalmitis, and ophthalmia nodosa in the setting of retained hairs that tend to migrate into the eye. The ultimate outcome may be permanent blindness.
- An uncommon but very concerning complication following caterpillar or moth exposures is the development of anaphylaxis in sensitized individuals.
Prognosis
- The prognosis is generally excellent.
Hossler EW. Caterpillars and moths. Dermatol Ther. Jul-Aug 2009;22(4):353-66. [Medline].
Balit CR, Geary MJ, Russell RC, Isbister GK. Prospective study of definite caterpillar exposures. Toxicon. Nov 2003;42(6):657-62. [Medline].
Carrijo-Carvalho LC, Chudzinski-Tavassi AM. The venom of the Lonomia caterpillar: an overview. Toxicon. May 2007;49(6):741-57. [Medline].
Hare T. Poisonous dwellers of the desert. Presented at: Southwest Parks & Monuments Association. 1995:1-32.
Henwood BP, MacDonald DM. Caterpillar dermatitis. Clin Exp Dermatol. Jan 1983;8(1):77-93. [Medline].
Horng CT, Chou PI, Liang JB. Caterpillar setae in the deep cornea and anterior chamber. Am J Ophthalmol. Mar 2000;129(3):384-5. [Medline].
Hossler EW. Caterpillars and moths: Part I. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol. Jan 2010;62(1):1-10; quiz 11-2. [Medline].
Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol. Jan 2010;62(1):13-28; quiz 29-30. [Medline].
Peters S. A Colour Atlas of Arthropods in Clinical Medicine. Wolfe Publishing Ltd; 1992:1-304.
Pinson RT, Morgan JA. Envenomation by the puss caterpillar (Megalopyge opercularis). Ann Emerg Med. May 1991;20(5):562-4. [Medline].
Seibert CS, Shinohara EM, Sano-Martins IS. In vitro hemolytic activity of Lonomia obliqua caterpillar bristle extract on human and Wistar rat erythrocytes. Toxicon. Jun 2003;41(7):831-9. [Medline].
Shama SK, Etkind PH, Odell TM, et al. Gypsy-moth-caterpillar dermatitis. N Engl J Med. May 27 1982;306(21):1300-1. [Medline].
Sridhar MS, Ramakrishnan M. Ocular lesions caused by caterpillar hairs. Eye. May 2004;18(5):540-3. [Medline].
Steele C, Lucas DR, Ridgway AE. Endophthalmitis due to caterpillar setae: surgical removal and electron microscopic appearances of the setae. Br J Ophthalmol. Apr 1984;68(4):284-8. [Medline].
Stipetic ME, Rosen PB, Borys DJ. A retrospective analysis of 96 "asp" (Megalopyge opercularis) envenomations in Central Texas during 1996. J Toxicol Clin Toxicol. 1999;37(4):457-62. [Medline].
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