Unsaturated pyrrolizidine alkaloids are hepatotoxic, that is, damaging to the liver. PAs also cause hepatic veno-occlusive disease and liver cancer. PAs are tumorigenic. Disease associated with consumption of PAs is known as pyrrolizidine alkaloidosis.
The venom is what causes the symptoms. The main symptoms are pain, itching, swelling and redness at the sting site. Severe pain or burning at the site lasts 1 to 2 hours. Itching often follows the pain. Swelling. The bee sting may swell for 48 hours after the sting. The swelling can be small or large.
Signs usually occur within about 20 minutes of the bite. Animals should be observed for at least 12-24 hours after a reaction, as mild symptoms may progress in severity. The stings of bees, wasps, and ants often occur on hairless areas such as the stomach and feet, but are most common on the face, head, or inside the mouth.