A 64-year-old Caucasian woman sought a dermatological consultation 4 days after returning from a holiday in a rural area of the Southeast region of Brazil. She reported an acute painful sensation on her exposed chest after feeling something fall on her from an orange tree. Within a few minutes, the area became red, swollen, and severely painful. On examination, she had sequential petechial purpuric lesions, in a linear and parallel distribution pattern (Figure A). Dermoscopy of the lesion (DermaLite DL100™; 3Gen Inc., San Juan Capistrano, CA), demonstrated purpuric macules with overlying necrotic scales.
Sequential petechial purpuric lesions, with a linear and parallel distribution pattern. Upper left: Saturniidae caterpillar.
The skin appearance and the sudden pain after contact with a tree are strongly suggestive of caterpillar envenomation (erucism)11. Haddad Jr V, Cardoso JLC, Lupi O, Tyring SK. Tropical dermatology: venomous arthropods and human skin: Part I: Insecta. J Am Acad Dermatol. 2012;67(3):331.e1-14.. Caterpillars of the Saturniidae family have hollow-body spines connected to venom glands11. Haddad Jr V, Cardoso JLC, Lupi O, Tyring SK. Tropical dermatology: venomous arthropods and human skin: Part I: Insecta. J Am Acad Dermatol. 2012;67(3):331.e1-14.,22. Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol . 2010;62(1):13-28.. When the spines penetrate the skin, they inject toxins and invoke the classical manifestations. The marks have a train tracks appearance and are caused by the distribution of the spines11. Haddad Jr V, Cardoso JLC, Lupi O, Tyring SK. Tropical dermatology: venomous arthropods and human skin: Part I: Insecta. J Am Acad Dermatol. 2012;67(3):331.e1-14.,22. Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol . 2010;62(1):13-28..The combination of skin marks and intense local pain (sometimes with simultaneous lymphadenopathy), indicates a diagnosis of erucism22. Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol . 2010;62(1):13-28..
Saturniidae caterpillars (Figure A) are distributed mainly in tropical regions, but they can live in temperate climates11. Haddad Jr V, Cardoso JLC, Lupi O, Tyring SK. Tropical dermatology: venomous arthropods and human skin: Part I: Insecta. J Am Acad Dermatol. 2012;67(3):331.e1-14.. Although caterpillars of other moth families (i.e., Megalopygidae) may also cause lesions with a similar appearance, the marks are not as clear as those of the Saturniidae family. Treatment consists of cold compresses and topical anesthetics, regardless of the moth species22. Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol . 2010;62(1):13-28.,33. Haddad Jr V, Lastoria JC. Envenomation by caterpillars (erucism): proposal for simple pain relief treatment. J Venom Anim Toxins incl Trop Dis. 2014;20:21..
REFERENCES
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1Haddad Jr V, Cardoso JLC, Lupi O, Tyring SK. Tropical dermatology: venomous arthropods and human skin: Part I: Insecta. J Am Acad Dermatol. 2012;67(3):331.e1-14.
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2Hossler EW. Caterpillars and moths: Part II. Dermatologic manifestations of encounters with Lepidoptera. J Am Acad Dermatol . 2010;62(1):13-28.
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3Haddad Jr V, Lastoria JC. Envenomation by caterpillars (erucism): proposal for simple pain relief treatment. J Venom Anim Toxins incl Trop Dis. 2014;20:21.
Publication Dates
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Publication in this collection
Jul-Aug 2018
History
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Received
23 Nov 2017 -
Accepted
15 Dec 2017
