Pseudoallergy | |
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Other names | Nonallergic hypersensitivity |
Specialty | Dermatology, Rheumatology, Internal medicine |
Causes | Direct mast cell activation through non-IgE receptors |
Pseudoallergy, sometimes known as nonallergic hypersensitivity, is a type of hypersensitivity reaction mostly described in the context of drug allergy. The mechanism is somewhat similar to the type 1 hypersensitivity in the Gell and Coombs classification in that the effector cell is also mast cell. In pseudoallergic reaction, the mast cell is directly activated, rather than through the mediation of Immunoglobulin E (IgE). Therefore, it is also known as direct mast cell activation.[1][2]
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), along with certain food ingredients and additives like tartrazine, benzoates, and salicylates, are the most common causes of pseudoallergic reactions. Since these reactions don't require IgE sensitization, they may manifest themselves after only one exposure. Doses-dependent, pseudoallergic reactions typically involve substances that are chemically unrelated to each other.[3]
The lack of information in skin tests and serology makes the diagnosis challenging. Nonallergic hypersensitivity is diagnosed on the basis of symptoms. Oral challenge tests can be used to confirm pseudoallergy in the proper clinical context, i.e. a person consumes progressively larger quantities of a suspected allergen under medical supervision.[4][5]