Anaphylactic shock is the maximum variant of an allergic reaction of the immediate type (type I). This is an overreaction of the immune system to various substances (e.g. bee/wasp sting, food, medication). This leads to the symptoms of an allergic reaction (itching, wheals, redness) and in addition to a drop in blood pressure, even to circulatory failure.
In addition, breathing difficulties, palpitations, urge to urinate and defecate, even wetting and defecation can occur. This is an acutely life-threatening reaction. An emergency doctor should therefore be alerted and first aid measures should be started. Some patients have an “emergency kit” with which they can already start their own therapy on site.
In case of an anaphylactic shock, typical symptoms of the allergic immediate reaction (anaphylaxis) occur. The anaphylactic reaction is divided into four stages, which should allow an assessment of the severity of the reaction. Although these stages can occur consecutively, a higher stage can be reached right at the beginning.
Typical symptoms of an allergic reaction are Itching, which can be localised or spread over the whole body; wheals (urticae) raised from the actual skin level – these can change shape and merge; reddening of the face (see flush syndrome) and the skin in general with a sensation of heat. Restlessness and fear are also common. In the case of severe reactions, heart palpitations, a drop in blood pressure, urge to defecate, nausea, salivation and breathing difficulties can also occur.
Shock in the narrower sense of the word is when there is also very low blood pressure with circulatory failure and life-threatening shortness of breath with swelling of the airways. This can also lead to unconsciousness. In extreme cases, death can occur through respiratory arrest and/or circulatory arrest.
Any substance that can cause an allergy can lead to anaphylactic shock. It is typical that only the second contact leads to such a reaction. However, since allergens are common substances, the first contact is often not consciously perceived.
Common triggers are: Numerous drugs can trigger allergic reactions up to anaphylactic shock. Allergic reactions are relatively common, whereas anaphylactic shock as a maximum variant is relatively rare. Drugs that trigger allergic reactions are e.g. antibiotics (especially those from the penicillin group), painkillers (such as aspirin, ibuprofen, paracetamol, metamizole) and X-ray contrast media.
Many foods also trigger allergies. Allergies to nuts, soya and shellfish (e.g. lobster, crabs, mussels) are particularly common. Local differences in the frequency of such allergies can be determined.
For example, peanut allergies are more common in the USA than in Europe. This is attributed to the high consumption of peanut butter. Bee stings and wasp stings can often trigger anaphylactic reactions.
An allergic reaction is defined as a swelling of the stinging site of more than 10 cm and the symptoms of an allergic reaction. An anaphylactic reaction can be triggered in particular by breathing in dust containing latex. A frequent contact with latex leads to a higher risk of developing a latex allergy.
Therefore, especially people who have a lot of contact with latex at work are affected (especially in the medical field, as many disposable gloves are made of latex). Pollen is often the trigger for runny nose and tears in the context of allergic rhinoconjunctivitis. In rare cases they can also lead to anaphylactic reactions. Bacterial components can also cause severe allergic reactions in the context of infections. These can also occur during therapy with antibiotics, when the bacteria decompose and many bacterial fragments enter the blood.