Question: What causes erucism?

Context:
Erucism is a skin reaction to envenomation from certain poisonous caterpillar bristles.
Although many tropical insects carry infectious diseases, cutaneous injury can occur by other mechanisms, for example erucism (envenomation by caterpillars) or lepidopterism (dermatitis from moths).
We present a case of erucism (caterpillar dermatitis) in a British serviceman deployed in Croatia on Operation Resolute. 
The hair on the dorsum of the last instar larvae of the moth may cause urticarial reactions (erucism) as well as eye problems and temporary blindness.
In the South of Brazil during the last years caterpillars of this butterfly caused a great number of cases of erucism including some deaths. 
Urticating moths (genus Hylesia and Anaphae) protect their eggs and young caterpillars with urticating hairs, thus it is very ambiguous to label erucism as the contact dermatitis produced by caterpillar production or Lepidopterism as the contact dermatitis caused by moth urticating hairs.
Erucism is defined as urtication by Lepidoptera larvae. 
Specific syndromes caused by Lepidoptera include erucism (cutaneous reactions from contact with caterpillars, moths, or cocoons), lepidopterism (systemic involvement), ophthalmia nodosa (ocular involvement), dendrolimiasis and pararamose (each with joint symptoms relating to a specific species of caterpillar), lonomism (a severe hemorrhagic disease related to Lonomia species), and seasonal ataxia (related to ingestion of Anaphe venata). 
Specific syndromes caused by Lepidoptera include erucism (cutaneous reactions from contact with caterpillars, moths, or cocoons), lepidopterism (systemic involvement), ophthalmia nodosa (ocular involvement), dendrolimiasis and pararamose (each with joint symptoms relating to a specific species of caterpillar), lonomism (a severe hemorrhagic disease related to Lonomia species), and seasonal ataxia (related to ingestion of Anaphe venata).
Urticating moths (genus Hylesia and Anaphae) protect their eggs and young caterpillars with urticating hairs, thus it is very ambiguous to label erucism as the contact dermatitis produced by caterpillar production or Lepidopterism as the contact dermatitis caused by moth urticating hairs.
Erucism is defined as urtication by Lepidoptera larvae.
Erucism is defined as urtication by Lepidoptera larvae.
Specific syndromes caused by Lepidoptera include erucism (cutaneous reactions from contact with caterpillars,
thus it is very ambiguous to label erucism as the contact dermatitis produced by caterpillar production or Lepidopterism as the contact dermatitis caused by moth urticating hairs.
Specific syndromes caused by Lepidoptera include erucism (cutaneous reactions from contact with caterpillars, moths, or cocoons), lepidopterism (systemic involvement), ophthalmia nodosa (ocular involvement), dendrolimiasis and pararamose (each with joint symptoms relating to a specific species of caterpillar), lonomism (a severe hemorrhagic disease related to Lonomia species), and seasonal ataxia (related to ingestion of Anaphe venata).
Urticating moths (genus Hylesia and Anaphae) protect their eggs and young caterpillars with urticating hairs, thus it is very ambiguous to label erucism as the contact dermatitis produced by caterpillar production or Lepidopterism as the contact dermatitis caused by moth urticating hairs.

Answer: Erucism is defined as urtication by Lepidoptera larvae. It is a skin reaction to envenomation from certain poisonous caterpillar bristles. The hair on the dorsum of the last instar larvae of the moth may cause urticarial reactions (erucism) as well as eye problems and temporary blindness.