What’s Eating You? Megalopyge opercularis

Abstract

Caterpillars-the larval form of butterflies and moths-belong to the order Lepidoptera. Some identified caterpillars from this order have developed venomous defense mechanisms such as irritating hairs and spines to protect themselves from predators. Direct contact to allergenic caterpillars' hairs can cause human disease. Cutaneous lesions following caterpillar envenomation can range from mild localized inflammatory signs and pain to a worsening appearance of vesicles, bullae, erosions, petechiae, necrosis, and ulceration. This review addresses the varied general manifestations caused by venomous lepidopteran exposure with special focus on the adverse cutaneous manifestations and therapeutic options of Megalopyge opercularis, the caterpillar of the flannel moth.

Poisonous, Venomous, or Harmless?

“…2,8 The color changes resemble similar discolorations caused by purple toe syndrome or acute arterial occlusion. 8,9 They resolve spontaneously over days to weeks. 8,9 The most common site of discoloration is on the foot, followed by other uncovered areas of the body, including the eyelids, face, hands, and arms.…”

“…2,[8][9][10][11] The quinone constituents can cause painful discoloration of the skin and pigment changes, with dark tones of red, blue, and black (Figure 5). 2,8 The color changes resemble similar discolorations caused by purple toe syndrome or acute arterial occlusion. 8,9 They resolve spontaneously over days to weeks.…”

“…2,8,9 Investigators have cautioned that millipede-inflicted discolorations can be mistaken for bruising from child abuse, especially if covered areas of the body are involved (Figure 5). 8,9 Centipedes may be encountered accidentally indoors or outdoors in leaf litter, decaying wood, or compost piles or when trying to exterminate them indoors. Centipede stings cause burning pain that can last from 30 min to 3 d. Most sting sites will have 2 puncture wounds made by paired forcipules.…”

“…2,8,9 Covered parts of the body are less commonly affected by discoloration. 2,8,9 Investigators have cautioned that millipede-inflicted discolorations can be mistaken for bruising from child abuse, especially if covered areas of the body are involved (Figure 5). 8,9…”

Identification of Novel Toxin Genes from the Stinging Nettle Caterpillar Parasa lepida (Cramer, 1799): Insights into the Evolution of Lepidoptera Toxins

“…Caterpillar venom varies in its effect from mild to severe. Local effects include contact dermatitis, e.g., allergic reaction, edema, erythema, and local tissue damage; systemic effects include hemostatic disturbance, acute kidney injury, intracerebral bleeding, and pararama-associated phalangeal periarthritis [ 15 , 18 , 19 , 20 ].…”