Diagnostic tools in Rhinology EAACI position paper

There are several reasons for accurate investigation of upper airways disorders like allergic rhinitis [1] and rhinosinusitis [2]. The first reason relates to the fact that such problems impact very significantly upon patients' quality of life and that well directed treatment can ameliorate the impairment of quality of life. The second is that some of these disorders are severe with significant morbidity and even mortality, and that presentation often occurs in the upper airway. Early diagnosis and effective management can prevent serious consequences, like in Wegeners' granulomatosis. The third reason relates to the fact that upper respiratory tract problems exacerbate lower respiratory symptoms and may extend to involve the lower respiratory tract. The nose is an air conditioner; filtering, warming and humidifying over 10,000 liters of air daily before it progresses to the lungs.The nasal passages and associated structures bear the brunt of environmental contact being the first site of allergen, microbial and particle deposition. As a consequence the upper airway is the location of a highly developed innate and adaptive immune system. Effective mucociliary clearance is vital for respiratory health as evidenced by the effects of defects such as primary ciliary dyskinesia (PCD) and cystic fibrosis (CF). Lower airways disease is often preceded by nasal and sinus disease leading to a window of opportunity for early diagnosis and possibly prevention of severe complications. For example measurement of nasal nitric oxide is simple and quick and very low levels can alert the physician to the possibility of PCD before major lung damage is sustained, thus allowing the benefit of early physiotherapy.Inflammatory airways diseases usually start in the nose. This observation does not only hold true for allergic and non-allergic rhinitis in older children and adults which can progress to asthma, but also for respiratory occupational disease, and for rhinosinusitis which can be t