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Caterpillar Envenomation Clinical Presentation

  • Author: Robert L Norris, MD; Chief Editor: Scott H Plantz, MD, FAAEM  more...
 
Updated: Jul 19, 2016
 

History

While the history of exposure related temporally to the onset of signs and symptoms may be clear, the diagnosis can be challenging. Maintain a high index of suspicion when patients present with unexplained acute dermatitis, rhinitis, conjunctivitis, or wheezing during months when caterpillars are numerous. In some regions of the world, the diagnosis becomes clear when clusters of seemingly unrelated cases start to present.

Onset of acute dermatitis due to hair exposure may immediately follow exposure or may be delayed 8-12 hours.

Intense pruritus, local pain or soreness (less common), and erythematous raised rash, blisters, and bruising at the site may occur.[1, 2] Skin necrosis has occurred following prolonged exposure to toxic hairs. With most toxic caterpillars, systemic symptoms are unusual in the absence of respiratory exposure.

Respiratory exposure may precipitate acute rhinitis, tearing, cough, dyspnea, respiratory distress, wheezing, and chest pain. This syndrome may need to be differentiated from the rare case of anaphylaxis.

Ocular exposure may initiate an acute conjunctivitis with severe pain, tearing, and redness. Visual acuity can be reduced as inflammation progresses.

Stings by venomous caterpillars result in immediate, localized, severe, burning pain, which can radiate proximally and be severe enough to inhibit movement of the extremity (pseudoparalysis). Redness and swelling with slight bruising may occur at the site. Over the first few days, the patient may note the development of small blisters, which can become hemorrhagic. Local findings, including pain, may persist for several days.

Systemic complaints may occur within minutes of the sting, although they usually occur within 2 hours. These complaints include headache, dizziness, restlessness, nausea and vomiting, malaise, swollen or tender lymph nodes, muscle spasms, rapid heart rate, and, in exceptional cases, altered mental status. Systemic symptoms usually resolve in 24 hours.

Following stings by some of the New World caterpillars in the family Saturniidae, which contain a fibrinolytic component to their venoms, patients may note scattered bruising (onset in 8-72 h) and bleeding from any of a number of sites (eg, gingival bleeding, hematuria). Intracranial bleeding and acute renal failure (rarely chronic renal failure) are possible complications. Coagulopathy can last 2-5 weeks.

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Physical

Local findings include erythematous papules that tend to congregate around the face, neck, trunk, arms, wrists, and hands and may become confluent; vesicles; local purpura; or ecchymosis.

Systemic signs may include a low-grade fever.[3] Anaphylaxis is reported.[4]

Findings of respiratory exposure include acute rhinitis, tearing, respiratory distress, and wheezing.

Ocular exposure can result in acute conjunctivitis. Following penetration of the cornea, findings include keratitis,[5] acute uveitis, ophthalmia nodosa,[6] and retinochoroiditis.

Local findings from stings can include erythema, edema, small petechiae or hemorrhagic papules, vesicles, bullae, and pseudoparalysis of the extremity because of pain. Following M opercularis stings, the site may take on a gridlike pattern matching the distribution of the creature's spines.

Systemic findings from stings can include restlessness, lymphangitis, oropharyngeal edema, lymphadenopathy, muscle spasms, tachycardia, altered mental status (unusual), seizures, and hypotension.[7, 8]

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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.

Following stings by some of the New World caterpillars in the family Saturniidae, which contain a fibrinolytic component to their venoms, patients may note scattered bruising (onset in 8-72 h) and bleeding from any of a number of sites (eg, gingival bleeding, hematuria).[9, 10, 11] Intracranial bleeding and acute renal failure (rarely chronic renal failure) are possible complications.[12] Coagulopathy can last 2-5 weeks.

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Contributor Information and Disclosures
Author

Robert L Norris, MD Professor, Department of Emergency Medicine, Stanford University Medical Center

Robert L Norris, MD is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, International Society of Toxinology, American Medical Association, California Medical Association, Wilderness Medical Society

Disclosure: Nothing to disclose.

Specialty Editor Board

John T VanDeVoort, PharmD Regional Director of Pharmacy, Sacred Heart and St Joseph's Hospitals

John T VanDeVoort, PharmD is a member of the following medical societies: American Society of Health-System Pharmacists

Disclosure: Nothing to disclose.

Gino A Farina, MD, FACEP, FAAEM Professor of Emergency Medicine, Hofstra North Shore-LIJ School of Medicine at Hofstra University; Program Director, Department of Emergency Medicine, Long Island Jewish Medical Center

Gino A Farina, MD, FACEP, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Scott H Plantz, MD, FAAEM Associate Clinical Professor of Emergency Medicine, Department of Emergency Medicine, University of Louisville School of Medicine

Scott H Plantz, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine

Disclosure: Nothing to disclose.

Additional Contributors

Samuel M Keim, MD, MS Professor and Chair, Department of Emergency Medicine, University of Arizona College of Medicine

Samuel M Keim, MD, MS is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Public Health Association, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

References
  1. Bonamonte D, Foti C, Vestita M, Angelini G. Skin Reactions to pine processionary caterpillar Thaumetopoea pityocampa Schiff. ScientificWorldJournal. 2013. 2013:867431. [Medline].

  2. Iacobucci G. Oak moth caterpillar that causes rash is spreading in southeast England. BMJ. 2013 May 8. 346:f2964. [Medline].

  3. Wills PJ, Anjana M, Nitin M, Varun R, Sachidanandan P, Jacob TM, et al. Population Explosions of Tiger Moth Lead to Lepidopterism Mimicking Infectious Fever Outbreaks. PLoS One. 2016. 11 (4):e0152787. [Medline].

  4. DuGar B, Sterbank J, Tcheurekdjian H, Hostoffer R. Beware of the caterpillar: Anaphylaxis to the spotted tussock moth caterpillar, Lophocampa maculata. Allergy Rhinol (Providence). 2014 Jul. 5 (2):113-5. [Medline].

  5. Bleriot A, Couret C, Lebranchu P, Le Meur G, Weber M. [Keratitis due to foreign bodies from a processionary caterpillar nest]. J Fr Ophtalmol. 2015 Jan. 38 (1):85-6. [Medline].

  6. Prasad SC, Korah S. Rare Presentation of Ophthalmia Nodosa. Middle East Afr J Ophthalmol. 2015 Oct-Dec. 22 (4):520-1. [Medline].

  7. Casado Verrier E, Carro Rodríguez MA, de la Parte Cancho M, Piñeiro Pérez R. [Systemic reaction after pine processionary caterpillar ingestion. Conservative management?]. Arch Argent Pediatr. 2016 Jun 1. 114 (3):e151-4. [Medline].

  8. MacKinnon JA, Waterman G, Piastro K, Oakes J, Pauze D. Oropharyngeal Edema in an 8-Month-Old Girl after Woolly Bear Caterpillar Exposure. J Emerg Med. 2015 Nov. 49 (5):e147-9. [Medline].

  9. Sánchez MN, Mignone Chagas MA, Casertano SA, Cavagnaro LE, Peichoto ME. [Accidents with caterpillar Lonomia obliqua (Walker, 1855). An emerging problem]. Medicina (B Aires). 2015. 75 (5):328-33. [Medline].

  10. Maggi S, Faulhaber GA. Lonomia obliqua Walker (Lepidoptera: Saturniidae): hemostasis implications. Rev Assoc Med Bras. 2015 May-Jun. 61 (3):263-8. [Medline].

  11. Medeiros DN, Torres HC, Troster EJ. Accident involving a 2-year-old child and Lonomia obliqua venom: clinical and coagulation abnormalities. Rev Bras Hematol Hemoter. 2014 Nov-Dec. 36 (6):445-7. [Medline].

  12. Schmitberger PA, Fernandes TC, Santos RC, de Assis RC, Gomes AP, Siqueira PK, et al. Probable chronic renal failure caused by Lonomia caterpillar envenomation. J Venom Anim Toxins Incl Trop Dis. 2013 Jun 3. 19 (1):14. [Medline].

  13. Lipkova B, Gajdosova E, Kacerik M, Duranova M, Izak MG. Caterpillar setae penetration in an eye: long-term follow-up. Retin Cases Brief Rep. 2013 Summer. 7 (3):252-4. [Medline].

  14. Hossler EW. Caterpillars and moths. Dermatol Ther. 2009 Jul-Aug. 22(4):353-66. [Medline].

 
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Caterpillar envenomations. Puss caterpillar or asp. Photo courtesy of the Arizona Poison and Drug Information Center.
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