Allergies:

The most widely known allergic disorder is allergic rhinitis, or "hay fever". Strictly speaking however, an allergy can assume different presentations such as respiratory tract disorders, skin disorders (in particular, urticaria, eczema ), ocular disorders (conjunctivitis), and bronchial disorders (asthma). 

The aim of this section is to provide description of different allergic disorders, their main features and diagnosis. Unrecognised up to the early XXth century, allergic disease has become extremely prevalent over the last thirty years and rank fourth on the list of chronic disease according to recent WHO data.