Allergic diseases are rare in areas with high helminth parasite exposure and common where helminth exposure is lacking or significantly reduced, such as urban areas of developing countries and industrialized nations. To test the hypothesis that helminths protect against allergies, Dr Carsten Flohr conducted both clinical and laboratory studies at the Oxford University Clinical Research Unit in Ho Chi Minh City (Saigon), Vietnam. Dr Flohr's work has shown that gut parasites, such as hookworm and Ascaris lumbricoides, can suppress allergic skin sensitisation to environmental allergens, an effect that is probably mediated by parasite-induced anti-inflammatory cytokines, including interleukin-10. The ultimate aim is to develop allergy drugs from parasite-derived products.