Anosmia (lack of smell) also is common, as inflammation within the nose and sinuses likely reaches the olfactory receptors.The respiratory reactions to NSAIDs vary in severity, ranging from mild nasal congestion and eye watering to lower respiratory symptoms including wheezing, coughing, an asthma attack, and in rare cases, anaphylaxis. In addition to the typical respiratory reactions, about 10% of patients with AERD manifest skin symptoms such as urticaria and/or gastrointestinal symptoms such as abdominal pain or vomiting during their reactions to aspirin.In addition to aspirin, patients also react to other NSAIDs such as ibuprofen, and to any medication that inhibits the cyclooxygenase-1 (COX-1) enzyme, although paracetamol (acetaminophen) in low doses is generally considered safe. NSAIDs that are highly selective in blocking COX-2 and do not block its closely related paralog, COX-1, such as the COX-2 inhibitors celecoxib and rofecoxib, also are regarded as safe. Nonetheless, recent studies do find that these types of drugs, e.g. acetaminophen and celecoxib, may trigger adverse reactions in these patients; caution is recommended in using any COX inhibitors. In addition to aspirin and NSAIDs, consumption of even small amounts of alcohol also produces uncomfortable respiratory reactions in many patients. Cause
The disorder is thought to be caused by an anomaly in the arachidonic acid metabolizing cascade that leads to increased production of pro-inflammatory cysteinyl leukotrienes, a series of chemicals involved in the bodys inflammatory response.
Aspirin exacerbated respiratory disease (AERD),  also termed aspirin-induced asthma, is a medical condition initially defined as consisting of three key features: asthma, respiratory symptoms exacerbated by aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), and nasal polyps. The symptoms of respiratory reactions in this syndrome are hypersensitivity reactions to NSAIDs rather than the typically described true allergic reactions that trigger other common allergen-induced asthma, rhinitis, or hives. The NSAID-induced reactions do not appear to involve the common mediators of true allergic reactions, immunoglobulin E or T cells. Rather, AERD is a type of NSAID-induced hypersensitivity syndrome. EAACI/WHO classifies the syndrome as one of five types of NSAID hypersensitivity or NSAID hypersensitivity reactions. Signs and symptoms
The various non-allergic NSAID hypersensitivity syndromes affect 0.5–1.9% of the general population, with AERD affecting about 7% of all asthmatics and about 14% of adults with severe asthma. AERD, which is slightly more prevalent in women, usually begins in young adulthood (twenties and thirties are the most common onset times, although children are affected by it and present a diagnostic problem in pediatrics) and may not include any other allergies. Most commonly the first symptom is rhinitis (inflammation or irritation of the nasal mucosa), which may manifest as sneezing, runny nose, or congestion. The disorder typically progresses to asthma, then nasal polyposis, with aspirin sensitivity coming last.