Pot allergy is probably widely underreported

Humans are often allergic to pollen and other chemical compounds in weeds. Most of the time, if an allergy is life-threatening—or even just way-of-life-threatening—you'll report it to your doctor, and she'll get you treatment. But, when the weed in question is illegal, the normal process breaks down. Cases of marijuana allergy are rare in the medical literature, but a recent study suggests that they're a lot more common in real life. Reactions range from the annoying (runny noses) to dangerous (anaphylactic shock), but if patients and doctors can't speak freely to one another then patients miss out on treatment and medicine loses valuable information. (Via Kerri Watcher)