Honey Bee, Hornet and Wasp Stings and Allergy
Honey bee, hornet and wasp stings are responsible for disease in humans. Anaphylaxis, a life-threatening reaction may develop in approximately 3% of all adults and about 1% of children after honey bee, hornet or wasp stings. Four situations should be distinguished in terms of risk:
1. Normal local reaction: pain, redness, swelling: elicited by substances injected by the insect and the body's response. Such a reaction is normal. The risk of a future dangerous reaction in a person suffering only a normal local response is not different than the risk for the general population.
2. Large local reaction: in which the body's response to the injected substances is exaggerated, leading to large areas of swelling, generally over 20 cm in the larger dimension. The risk of a dangerous future reaction in a person suffering a large local reaction is considered low.
3. Cutaneous generalized skin reaction without additional systemic component: this reaction comprises a cutaneous response that is beyond the site of the insect sting. In this reaction a skin rash is present far and without contiguity to the site of the original sting. The risk of a dangerous reaction in a person suffering a cutaneous systemic reaction is considered low in children but in adults it is significant and is an indication for immunotherapy (allergy vaccines).
4. Anaphylaxis: This reaction may comprise manifestations in different systems and for the diagnosis to be made at least two of the following systems must be involved: skin (swelling, rash), respiratory (shortness of breath, choking), heart - vascular (low blood pressure, extreme weakness, fainting). Anaphylactic reaction is very dangerous and can result in death within a short time after the sting. The risk of a future dangerous reaction in a person who survived an anaphylactic reaction is significant and is an indication for immunotherapy (allergy vaccines).
The physician's diagnosis requires information provided by the patient: insect responsible for the sting, timing of symptoms, type of symptoms, findings in the physical examination, blood pressure and more. In addition, when anaphylaxis or a generalized cutaneous reaction is suspected, insect sting allergy should be demonstrated using skin tests and / or laboratory tests, and sometimes both. In some cases it is difficult to confirm an insect sting allergy and it may be necessary to repeat the tests after 4-6 weeks.
If the physician considers the possibility of a dangerous reaction due to allergy to insect stings, the patient must be instructed to avoid exposure to the suspected insects (for example to avoid approaching rural areas) and to be equipped with an automatic syringe of adrenaline (EpiPen) available to him at any given moment. EpiPen injection is a lifesaving emergency treatment. However, immediate contact to an emergency service should be made in order to provide additional treatment and to transfer the patient to the nearest emergency room, even if there is an improvement after EpiPen injection.
The physician will determine if it is an allergic reaction and what is the risk for a future reaction. According to these data the physician will decide if the patient needs immunotherapy (allergy vaccines). Immunotherapy consists of two stages: the first stage is the stage of building the protection. In this step the vaccine dose is increased until a protective dose is reached. There are different protocols including a rush protocol. Rush protocols provide rapid protection at the cost of some controlled reactions during an intensive protocol of vaccines. After a protective dose is reached, the stage of maintenance starts. During maintenance the patient will receive immunotherapy generally once a month (there are also protocols with larger intervals) for 3-5 years. There are some cases in which the vaccinations cannot be stopped and must continue in a permanent fashion. Immunotherapy is effective in preventing severe reactions in people allergic to insect stings.