Large painful bite looking bump on side of neck, allergic reaction to bandaid covering it, now rash around neck, chest, legs, and arms. Very itchy!

Mgt suggestions. From your description, the area on the side of the neck may be an insect bite, and the total body rash part of an allergic reaction.Exam the neck area for any bite marks, stingers. I would suggest not attempting to remove the stinger. Applying Hydrocortisone and Calamine in combination with an antihistamine may provide relief. I agree that if you have any breathing problems, proceed to the ED.
Allergic reaction. If you are aware you are allergic to bandaid and you have had similar reaction in the past most likely exposure to the same agent caused another reaction. Benadryl (diphenhydramine) usually helps but if severe, especially if you develop trouble breathing you should get seen asap.