This is one of the main reasons (apart from the furtherance of Science) that I’m happy to take part in this study; I suffer from hayfever for about four months every year, and I was curious about which allergens I was sensitive to. Grass pollen showed up as I expected, leaving me with a larger welt than the positive control of histamine. Tree pollen also showed up, which would explain why my hayfever has been getting earlier in recent years. Less expected were the slight responses to dogs (just as well I prefer cats) and to peanuts (ironic, given how much I eat them). I’m wishing that I’d taken a photo of the marks.