Wasps sting but do not leave the stinger behind as bees do. Therefore, the wasp is able to sting again. Stings are typically treated with an injectable epinephrine if the person is allergic.
After a sting, keep the area clean and watch for signs of infection, such as redness, warmness to the touch and presence of pus. A mild over-the-counter pain reliever can be given for pain, and an antihistamine may lesson itching.
If nausea, vomiting, dizziness or tightening of the chest are present, call emergency services. If swelling doesn't subside after three days, medical attention is necessary. A sting in or around the mouth requires emergency medical care, as this can cause airways to swell, making breathing difficult.