<p>Immunotherapy</p><p>Patients with food or episodic allergies are usually prescribed antihistamines as these drugs counteract the effects of histamine, one of the major chemicals released in an allergic reaction. If sufficient antihistamine is given early enough, most allergic reactions will resolve.</p><p>Patients with allergy to unavoidable allergens, such as house dust mite and pollens will commonly find themselves needing repeated doses of antihistamines and may find that even with regular antihistamines, their symptoms break through. For these inhaled allergens (aeroallergens), regular preventative doses of antihistamines as well as local therapy with inhaled steroids and antihistamine eye-drops might be prescribed. If despite all of this treatment, the allergic disease persists and causes unpleasant symptoms, then an immunomodulatory strategy might be used.</p><p>The immunomodulatory strategy targets the immune response itself and aims to redirect it away from allergy and back toward a more healthy / normal immune response. For most pollens and foods, this normal immunity would be to ignore the allergen. To achieve this, we give small doses of the allergen in a form to help the immune system to respond differently. At the moment, this is a field of science that is developing quickly and improvements are occurring all the time. </p><p>At the present time, we are using these immunomodulatory strategies (also called immunotherapy or desensitisation) to treat allergy to grass and tree pollens principally.</p>