What’s Eating You? Caterpillars
Caterpillar envenomation is a worldwide problem, with manifestations ranging from dermatitis to iridocyclitis and a fatal hemorrhagic diathesis. This article focuses on the diagnosis and management of dermatoses related to caterpillars.
Practice Points
- Lepidopterism describes adverse reactions caused by the stings, hypersensitivity reactions, and lonomism (a hemorrhagic diathesis) of caterpillars, moths, and butterflies.
- Caterpillars can induce an adverse reaction by injecting venom stored in their bristles, inducing a foreign-body reaction to embedded bristles, or a combination of these mechanisms.
- A thorough history, skin scrapings, relevant examination of affected body parts (such as slit-lamp examination, in the case of eyes), and laboratory testing should be conducted to narrow the wide differential diagnosis associated with lepidopterism.
Prevention—People should wear proper protective clothing when outdoors in potentially infested areas. Measures should be taken to ensure that linens and clothing are not left outside in areas where setae might be carried on the wind. Infestation control is necessary if the population of caterpillars reaches a high enough level.
Conclusion
Several species of caterpillars and moths cause adverse reactions in humans: stings, hypersensitivity reactions, and lonomism. Although most reactions are self-limited, some might have more serious effects, including organ failure and death. Mechanisms of injury vary by species of caterpillar, moth, and butterfly; current research is focused on further defining venom components and signaling pathways to isolate potential targets to aid in the diagnosis and treatment of lepidopterism.
