Quercetin Is More Effective than Cromolyn in Blocking Human Mast Cell Cytokine Release and Inhibits Contact Dermatitis and Photosensitivity in Humans March 2012 free full text, with Theoharides http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3314669/ note that WSQ isn't defined, it's Water Soluble Quercetin An MOA discussed here is that Quercetin inhibits intracellular Ca++ increase, leading to degranulat5ion. I'd previoulsy read about quercetin increasing cAMP, which opposes the gAMP that leads to degranulation. A few quotes: "Moreover, cromolyn does not inhibit lung and mucosal mast cells". "Here we also show that WSQ is more effective than quercetin in blocking intracellular calcium increases in stimulated human mast cells, while cromolyn had no effect." "In conclusion, our results indicate that quercetin is more effective than cromolyn in inhibiting release of pro-inflammatory cytokines from human mast cells. Moreover, quercetin appears to significantly reduce contact dermatitis, photosensitivity and associated pruritus that are typically resistant to anti-histamines and cromolyn , . Quercetin is safe  and could be particularly useful in formulations that increase its solubility and oral absorption." Btw, elsewhere I've read that cromolyn was developed as the result of research into quercetin, it is in effect almost a synthetic quercetin.