Hay fever sufferers are being asked to help research at Nottingham University into a possible new treatment.
But the study is not for the squeamish - it involves deliberately infecting volunteers with hookworm to examine a possible link with the parasite.
Asthma and hay fever are on the rise in more affluent societies, but they are less common in the developing world.
Studies in Ethiopia suggest a link between hookworm infection and a lower risk of developing the illnesses.
A possible explanation for the rise of asthma and hay fever in the Western world is that better hygiene standards mean people are exposed to fewer infections, so their immune systems respond to normally harmless things.
In the developing world, where there are fewer cases, millions of people are infected with hookworm - a tiny parasite that lives in the bowel.
The Nottingham study will involve placing the larvae - or a placebo - on a volunteer's skin under a plaster for 24-hour periods.
This would be done over a 16-week period with monitoring by questionnaires and various breathing tests and taking blood samples.
The research follows a pilot study to establish how many hookworms would be needed to trigger an immune system response.
The infection is not contagious in developed countries with normal hygiene and sanitation.
At the end of the study, volunteers will be given a tablet to eradicate the hookworm infection from their bodies.
The research is being funded by the Wellcome Trust.