Root cause of allergies and allergic reactions can include toxicity overload, parasites, and depleted adrenals.

And allergies and histamines are linked. (Hence why people take Benadryl during an allergic reaction; Benadryl is an antihistamine. 

I advocate for getting to the root cause of the allergy/histamine issue using any of the preferred alternative medicine providers. 

For any allergic reaction I would use whatever I have on hand of the below products.

Things to look out for if you need to buy something on the spot:  products like Quercetin, stinging nettle, bromelain, and butterbur which are natural antihistamines.

The primary active ingredient in Benadryl is diphenhydramine hydrochloride which is an antihistamine that blocks H1 receptors. Alternatives are natural antihistamines like the products linked below. 

Top Natural Antihistamines:

Houttuynia FOUND HERE

Scutellaria FOUND HERE

Camu  FOUND HERE

You can find more below!