There are two types of allergic reactions. In the first type, the bite or sting site becomes excessively swollen and the patient may experience nausea, vomiting, dizziness and headache. The second type of allergic reaction can be life- threatening. A severe reaction can cause body-wide skin itching, hives, or puffiness of the eyes, nose, lips, tongue and throat. Abdominal pain and vomiting may develop.
Breathing difficulties are common.
The patient may collapse and go into shock. This kind of reaction presents a true medical emergency. Allergic reactions usually do not develop after the first sting. After a second or third sting, a reaction can develop. It is difficult to predict whether a person will have a life-threatening allergic reaction.