Causes explaining the epidemic of IgE-associated (allergic) diseases are unclear. MeDALL aims at generating novel knowledge on mechanisms of allergy initiation, in particular in childhood. To understand how a complex network of genetic and environmental factors leads to complex allergic phenotypes, a novel stepwise, large and integrative translational approach is needed. MeDALL includes experts in allergy, epidemiology, genetics, immunology, biology, animal models, biochemistry and systems biology combining strengths of ongoing EU projects. Results are fitted into new integrative complex mathematical models to establish suitable biomarkers for early diagnosis, prevention and targets for therapy of allergy-associated diseases such as asthma and atopic dermatitis. Ethics and gender are considered. MeDALL aims at improving health of European citizens, Europe competitiveness and innovative capacity while addressing global healt issues.