Diseases like asthma, rhinitis, conjunctivitis or atopic dermatitis may be due to allergic and also to non-allergic causes. The treatment of acute symptoms, the reliever treatment, is common to both allergic and non-allergic patients. Also, the controller or anti-inflammatory treatment is basically the same, whatever the cause. Allergic patients, in addition, are recommended specific treatment, depending on the offending allergen. This kind of treatment is directed to induce a state of tolerance, so the contact with the allergen will not cause symptoms. This is the aim of the allergy vaccines and of the procedures of desensitisation. Biologicals are drugs that act blocking the intermediate mechanisms of the allergic reactions; they are another approach to the treatment of allergic disorders.