Megalopyge opercularis Caterpillar Stings Reported to Texas Poison Centers

The Megalopyge opercularis caterpillar is covered with spines that break off and release venom on contact, resulting in severe pain, erythema, rash, and other adverse effects. In Texas, these caterpillars are abundant and of potential health threat. This study describes M opercularis caterpillar stings reported to Texas poison centers.

Cases were M opercularis caterpillar stings reported to Texas poison centers during 2000-2016. The distribution of stings was determined related to exposure circumstances and management.

There were 3484 M opercularis caterpillar stings reported during 2000-2016. The annual number of stings did not consistently change over the 17-year time period. The monthly number of stings was highest in July (12%) and October to November (59%). The patients were female in 53% of cases and aged 20 years or more in 56%. The sting occurred at the patient's own residence in 91% of cases. The patients were managed outside of a healthcare facility in 89% of cases; 93% of the patients were known or expected to have no or at most minor clinical effects. Dermal clinical effects were reported in 90% of cases, the most common being irritation/pain (84%), puncture/wound (45%), erythema/flushed (29%), and edema (15%).

M opercularis caterpillar stings reported to Texas poison centers were more frequently reported in July and October to November. Most of the patients were adults. The majority of patients were managed outside of healthcare facilities and did not have serious outcomes. Most of the adverse clinical effects were dermal in nature.