An allergy or intolerance describes a patient’s tendency towards hypersensitivity to a certain substance, so that an unwanted physiological reaction is expected after exposure to the substance, while most people would not exhibit such a reaction to that amount. The observed physiological changes are usually the result of an immunological reaction. The substances can be categorized as follows:

• Medicine
• Medicine category
• Ingredient/addition
• Nutrition
• Environmental factor
• Animal
• Plants
• Chemicals
• Inhaled allergenic

Purpose

Documenting and communicating allergies and intolerances is an important part of medical registration. It concerns the core of patient safety in general and medication safety in particular. In the execution of research, treatment and care, these patient characteristics constantly have to be taken into account. In principle, allergies and intolerances are also disorders and also could be entered as a problem. Nevertheless, these are usually entered separately. Allergies/Intolerances have a lot in common with warnings (Alert). An important difference is that with allergies and intolerances, a lot of detailed information is recorded on things such as the reactions to the causative substance. Furthermore, not every warning is a problem or medical condition.

Evidence Base

Complete medicinal allergies are insufficient when it comes to reactions to exposure to food products, items (such as bandages and band-aids), plants and animals. For these items, the standard allows the use of free text or the use of SNOMED CT code. However, no validated value set is currently available for this purpose for SNOMED CT.