If my 4 yo was stung by a wasp, should i take her to the hospital?

Bee stings: No. If this is the first sting, there is usually no severe reactions. Begin by applying cold compress at the site to prevent more swelling and reduce pain and monitor your child's appearance and vital signs. If this a repeat sting, watch closely for any allergic reaction like generalized hives and difficulty of breathing. If happen to have Epipen and/or benadryl, (diphenhydramine) give him both and rush to the ed.

Review: Not unless she is having an allergic reaction. If she has swelling of her mouth, throat, lips, tongue or hives with difficulty breathing - please call 911 as she would need immediate treatment. If previously diagnosed as allergic, use injectable Epinephrine (i.e., epi-pen or ana-kit) & transport to er. If she has significant allergy - should still be seen at er even if looking ok after epi-pen.