Causes of anaphylaxis. From where to start diagnosis?
Diagnosing allergic diseases, including the cause of anaphylaxis, is often a difficult and multistage process. Usually, as a first step, the allergist takes a very detailed clinical history [1]. Its purpose is to determine the circumstances under which the anaphylactic reaction occurred [2,3]. All information regarding both the clinical symptoms and the factors that may have triggered them is important [2].
The most significant tasks at this stage include determining the circumstances of the anaphylactic reaction, co-morbidities and/or ongoing medication. Medical records of hospitalisation after anaphylaxis are also carefully reviewed [3].
If an anaphylactic reaction occurs after a meal, it is important, in particular, to determine the composition of the meal as precisely as possible. It is not enough to know that you had fish, chips, and salad for lunch. It may be essential to know the species of fish and the exact composition of the salad [1,4].
In addition, for an anaphylactic reaction to occur, for some allergens, such as those found in foods, it is not enough just to ingest them. Also necessary is the presence of cofactors, i.e. factors external or directly related to the patient, which can amplify the allergic reaction [1,5]. These include:
- stress,
- physical exercise,
- menstruation,
- alcohol,
- non-steroidal anti-inflammatory drugs (NSAIDs),
- infection [5,6].
At this stage, every detail, even apparently irrelevant, can be crucial to correctly diagnosing the cause of anaphylaxis [1,4].
Molecular diagnosis of allergy and causes of anaphylaxis
Additional tests usually supplement the clinical history. These include skin tests and blood tests. These methods have previously mainly used allergen extracts, which are mixtures of proteins found in a particular allergenic source [7].
Unfortunately, in some cases, the collected clinical history and results of additional tests do not allow the identification of the allergen causing the anaphylaxis. This may be due to the absence or presence in too small quantities of these proteins in allergen extracts [4,6].
In such a situation, molecular diagnostics of allergy can be helpful. This method is a breakthrough in the diagnosis of allergic diseases, including anaphylaxis. It allows the determination of an individual sensitisation profile to individual allergen proteins. Even, or perhaps especially, against those that are absent or poorly represented in the allergen extract. In addition, this method can significantly reduce the time needed to correctly diagnose the cause of anaphylaxis, as it allows the determination of a sensitisation profile against almost 300 allergens in a single test [6,8].
Molecular diagnosis of allergy also allows the personalisation of therapeutic recommendations and has an impact on the patient’s quality of life [8]. Among patients who have experienced anaphylaxis, it makes it possible to pinpoint the cause of this reaction and to identify other allergen sources from which similar reactions may occur in the future [4,8].
Other diagnostic tests for anaphylaxis
Among other tests of great importance in the process of diagnosing anaphylaxis, attention should also be paid to testing serum or plasma tryptase levels. Currently, this is the most commonly used laboratory parameter to determine whether a patient has developed anaphylaxis. However, it is not a test that can determine the cause of anaphylaxis [2].
Summary
Anaphylaxis is the most severe systemic hypersensitivity reaction that can be life-threatening or even fatal. It is therefore essential to correctly identify its cause. However, the detailed clinical history that is the basis for diagnosing an anaphylactic reaction does not always make it possible to identify the life-threatening allergen. In such cases, molecular diagnostics of allergy may be helpful.
