Persons with aspirin sensitivity may develop asthma, rhinosinusitis, urticaria, stomach pain, and other symptoms that prohibit the use of aspirin and related compounds.
About 5-6 percent of the population is reported to have sensitivity or intolerance to acetylsalicylic acid, the active ingredient in the analgesic compound aspirin. Besides its effectiveness in reducing pain, aspirin is also used to help thin the blood and is frequently used as a preventive therapy in patients with vascular disease.
Symptoms of Aspirin Sensitivity
In people with aspirin intolerance, aspirin frequently induces bronchial constriction, causing wheezing and asthma. It's reported that about 10 percent of all people with aspirin have conditions that are induced or associated with aspirin sensitivity. People with aspirin intolerance are also more likely to develop rhinosinusitis (inflammation of the nasal mucosa and sinuses) and nasal polyps. The classic triad of aspirin sensitivity, nasal polyps, and asthma is known as Samter's syndrome.
Samter's syndrome is an inflammatory condition that is probably acquired and may be triggered by viral infection. The high levels of blood eosinophils characteristic of this syndrome suggest its allergic manifestations. About 10 percent of patients with this syndrome also develop urticaria or itching and angioedema (hives). Although this condition can develop in children and teenagers, it's more commonly seen in adults.
A second subset of people with aspirin sensitivity tends to develop urticaria, characterized by itching or hives, rather than nasal problems. Exposure to aspirin in people with this form of aspirin intolerance may cause acute urticaria, aggravate pre-existing or chronic urticaria, or act in conjunction with food or exercise to provoke conditions of anaphylaxis. People in this subset are also likely to react when exposed to certain food additives, particularly sulphites, and to food coloring agents. Other symptoms seen in people with aspirin sensitivity include flushing and abdominal pain.
Causes and Treatment of Aspirin Sensitivity
According to one theory people with aspirin sensitivity have defects in arachidonic acid metabolism that causes them to produce cysteinyl leukotrienes rather than prostaglandins. This leads to delayed mass cell degranulation with a subsequent release of histamine. It's also suspected that people with aspirin sensitivity develop these nasal conditions because of an altered pattern of neuropeptide-reactive nerve fibers in their nasal mucosa compared to people without intolerance to aspirin. It's also been reported that people with aspirin sensitivity have a higher number of leukotriene receptors than other people.
Treatment of aspirin sensitivity involves avoidance of aspirin and related medications and avoidance of respiratory irritants such as aerosol chemicals. Upper airway diseases related to aspirin sensitivity are commonly treated with bronchodilators and corticosteroids.
Aspirin Sensitivity in Autoimmune Disease
People with aspirin sensitivity can have cross-reactivity to other non-steroidal anti-inflammatory compounds such as ibuprofen and naproxen but there is no cross-reactivity with selective cyclo-oxygenase 2 inhibitors.
People with aspirin sensitivity exposed to aspirin and aspirin-like compounds show a modest elevation in immunoglobulin E suggesting that there is an immune-mediated component to this disorder. But overall, the mechanism behind aspirin sensitivity appears to be a pharmacologic or idiosyncratic drug reaction. The heightened immune response that occurs when people with aspirin sensitivity react to aspirin could worsen symptoms in other conditions including those associated with autoimmune disease.
Persons with rheumatic and vascular autoimmune disorders who have aspirin sensitivity frequently react to other non-steroidal anti-inflammatory agents although they respond well to corticosteroids and cyclooxygenase-2 inhibitors.
Resources:
Grattan CE, Aspirin Sensitivity and Urticaria, Clin Exp Dermatol, 2003 March; 28(2):123-127.
Zeitz, HJ, Bronchial asthma, nasal polyps, and aspirin sensitivity: Samter's syndrome, Clin Chest Med, 1988 Dec; 9(4): 567-576.
