Anaphylactic reactions to prednisone and Benadryl aren't common, but both are possible. In the case that true anaphylaxis is occurring, epinephrine is given followed by oxygen. This is usually followed by the administration of steroids and antihistamines. If a person is allergic to both prednisone and Benadryl, supportive measures and alternative medications can be used.
The better question is, how do you know that your dog is having an Anaphylactic reaction?
Anaphylaxis or Anaphylactic shock, typically.
Prednisone can be used for allergic disorders, and might help skin allergy, but is not used as antihistamine first aid. Two benadryl antihistamine capsules are better choice for immediate allergic reaction. The hospital will give benadryl as first aid for skin allergy.
Can antihistamines be taken at the same time as prednisone?Yes you can take Benadryl and Prednisone together. If you're having an allergic reaction, you can add Pepcid AC with the Benadryl to help control itching. Pepcid AC affects the histamines that Benadryl does not. The Prednisone will basically help treat the allergic reaction from the inside but doesn't help itching.
The medical term for an adverse reaction to treatment is "iatrogenic effect." This refers to any harm or side effect caused by a medical intervention, such as a medication, surgery, or other healthcare procedure.
If the symptoms are minor take an anti-histamine like Benadryl. If the symptoms are more serious go to ER and get help. You can go into anaphylactic shock if not treated quickly and properly.
Anaphylaxis is a life-threatening allergic reaction. The related adjective is "anaphylactic," but this isn't used to describe the person (i.e. you wouldn't write "She's anaphylactic for tree nuts.") Instead, it's used to describe the reaction ("She had an anaphylactic reaction to tree nuts.")
Anaphylactic shock.
An anaphylactic reaction.
If it is a non-anaphylactic reaction then how do you know it is a result from a vaccination? I would take my dog to my Veterinarian immediately and let him/her figure it out. That would be safest for your dog.
Dyspnea, hypotension, and loss of conciousness.
The reaction will vary from person to person but at the very least will entail pain and swelling in the area of the sting. The normal treatment would be an anti-histamine. In a worst way scenario, the person who has been stung could suffer anaphylactic shock and die but this is very rare.