What is the connection between worms and allergy? What does the hygiene hypothesis mean and how could it lead to new treatments and drugs for allergic patients? Which challenges and risks might be encountered? The author Corinna Schn”ller introduces the reader to new possibilities of using worm infections or parasite immunomodulators to fight allergic diseases. Parasitic worms have the intriguing capacity to modulate immune responses directed against them, and therefore can persist up to years in a host and this immunomodulation could be exploited in drug development. Secreted molecules of the parasites were found to be strongly involved in immune deviation and might bear themselves strong anti-allergic and anti-inflammatory potential. The use of a parasite compound in asthma and dermatitis models is analysed and potential mechanisms are investigated. Furthermore the influence of a gastrointestinal nematode infection on these allergy models is described. This publication is for readers with a scientific background or strong interest in the latest research on parasites and allergy, immunology and new opportunities for treatments.