99 © Springer Nature Switzerland AG 2021 C. Cingi et al. (eds.), Challenges in Rhinology, https://doi.org/10.1007/978-3-030-50899-9_12 I. Çakmak Karaer (*) Department of Otorhinolaryngology, Malatya Training and Research Hospital, Malatya, Turkey N. Bayar Muluk Department of Otorhinolaryngology, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey G. K. Scadding RNENT Hospital and University College, London, UK 12 Does Aspirin Desensitisation Work in N-ERD? Işıl Çakmak Karaer, Nuray Bayar Muluk, and Glenis K. Scadding 12.1 Introduction Aspirin (ASA, acetylsalicylic acid) has the most widespread use of any medication in the world. It plays a key role in the management of cardiovascular disease, espe- cially acute coronary syndromes (ACS) and chronic ischaemic heart disease (CIHD). It is used to prevent stroke and in the management of certain chronic rheu- matological disorders. Unfortunately, however, patients may become hypersensitive to aspirin or other agents of NSAID (nonsteroidal anti-inflammatory drug) type. This is particularly so when the agent is predominantly an inhibitor of the cyclo- oxygenase 1 (COX-1) enzyme [1]. Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD), also referred to as Samter’s triad, affects both the upper and lower air- ways and involves sinusitis of eosinophilic type, severe nasal polyp formation, asthma and hypersensitivity to COX-1-inhibiting drugs. It is an inflammatory dis- ease of escalating severity. Of N-ERD sufferers, 75% are also sensitive to alcohol [2]. N-ERD has a frequency of between 0.6% and 2.5% in general and is seen in 40% of cases where the patient develops asthma in adulthood and has chronic sinus- itis with nasal polyposis (CRS(+)NP). N-ERD is found in 7% of those with asthma, with a peak occurrence rate of 15% if asthma is severe [3]. The disorder is classified as progressive. The most common age for it to occur is age 30–34, and it is more usual in females than males. The initial presentation of N-ERD is frequently a