I've taken bromelain (enzyme) along with quercetin (flavinoid) mainly for sinusitis and allergy-induced asthma during the pollen season (heightened when combined with allergies to pets and foods). It works well to stop inflammation and histamine reactions and was how I was able to get off of my 3-yr daily Claritin & Sudafed habit and stop using inhalers. I only take it when symptomatic and my symptoms don't last for more than a day or two (as opposed to weeks), with my ability to breathe normally restored in 1-2 hrs after taking the supplements.

I haven't tried bromelain without the quercetin, however.

Mercola has an interesting article:
http://articles.mercola.com/sites/a...ial-report.aspx

All my food allergies seem to be related to proteins, so it makes sense that a proteolytic enzyme would be the one to help me even though I didn't know bromelain was proteolytic when I first read about the enzyme.