I keep meaning to blog this and forgetting:
Samter’s triad is a medical condition consisting of asthma, aspirin sensitivity, and nasal polyposis. It occurs in mid-life (twenties and thirties are the most common onset times) and may not include any allergies. It is also known as aspirin-sensitive asthma, aspirin triad, Widal’s triad, and aspirin induced asthma and rhinitis (AIAR).
The cause of Samter’s triad is unknown, but it is widely believed that the disorder is caused by an anomaly in the arachidonic acid cascade, which causes undue production of leukotrienes, a series of chemicals involved in the body’s inflammatory response. When prostaglandin production is blocked by NSAIDS like aspirin, the cascade shunts entirely to leukotrienes, producing the severe allergy-like effects. Samter’s triad
So, by suppressing one part of the arachidonic acid cascade (prostoglandin production), salicylates increase the production of leukotrienes.
In asthma, “Leukotrienes are involved in asthmatic and allergic reactions and act to sustain inflammatory reactions. [...] Leukotrienes also have a powerful effect in vasoconstriction particularly of venules and of bronchoconstriction, they also increase vascular permeability.”
Rosacea is characterised by vascular permeability and a leukotriene-rich response. Facial flushing is a common food chemical intolerance reaction.
Atopic dermatitis is characterised by increased leukotriene production, and has been treated successfully with leukotriene antagonists.
Something interesting is that milk thistle also suppresses the formation of leukotrienes during inflammatory response.