Insect Bites and Stings: How to Recognize and Treat Them, and When to Consult a Dermatologist

Insect Bites and Stings: How to Recognize and Treat Them, and When to Consult a Dermatologist

Summer is the time of year when we have the most opportunities to be outdoors, with all the positive consequences that this entails but also, unfortunately, some minor problems. Sometimes, in fact, it can happen that we are easy prey to insects and/or mites. How should you behave and what are the signs that require a visit to a dermatologist?

Stings from bees, wasps, and hornets, the so-called hymenoptera, are a very common phenomenon, though less frequent than bites from mosquitoes and sandflies. In Italy, about 15% of people are stung by a hymenopteran at least once in their life. Wasp stings are the most frequent, as wasps can be aggressive if you disturb them in a meadow or garden, or even simply while eating outdoors. Bees sting less frequently; hornets are rarer.

How do you tell which insect it is?

Unlike bees, wasps and hornets do not lose their stinger when they sting and can do so multiple times; for this reason, it is advisable to move away immediately after being stung. A bee, on the other hand, leaves its stinger in the skin and dies after stinging, because along with the stinger it also loses some glands and abdominal muscles.

Insect bites from mosquitoes and sandflies, however, should not cause concern, as they only result in a swelling of the skin with redness and intense itching, which can vary depending on the person and the insect. Stings from hymenoptera cause, in most cases, a local reaction: red swellings of the skin, of variable size (generally from 2 to 4 cm), with pain, redness, and swelling. This is a normal reaction, due to the venom injected by the hymenopteran, which contains dozens of irritating and toxic chemicals. A local reaction should not be a cause for concern and generally does not require therapy due to its short duration, which can range from a few minutes to a few hours depending on the sting site. Wasp stings can occasionally cause swelling that persists for a few days and causes itching if touched, especially during the night. In this case, it may be useful to consult a specialist for appropriate therapy, usually a topical corticosteroid and an oral antihistamine.

Only a small percentage of people, about 10%, may have more severe systemic reactions, such as nausea and/or vomiting, a drop in blood pressure, and/or widespread hives. In this case, a dermatological examination is essential. In extreme cases, finally, there can be the dreaded anaphylactic shock with a severe reduction in blood pressure that can even lead to death. Typically, there are preceding symptoms such as numbness, loss of consciousness, and even fainting. This clearly represents a medical emergency, after which you must immediately go to the Emergency Room.

Insect Bites and Stings: How to Recognize and Treat Them, and When to Consult a Dermatologist

Summer is the time of year when we have the most opportunities to be outdoors, with all the positive consequences that this entails but also, unfortunately, some minor problems. Sometimes, in fact, it can happen that we are easy prey to insects and/or mites. How should you behave and what are the signs that require a visit to a dermatologist?

Stings from bees, wasps, and hornets—the so-called hymenoptera—are a very common phenomenon, though less frequent than bites from mosquitoes and sandflies. In Italy, about 15% of people are stung by a hymenopteran at least once in their life. Wasp stings are the most frequent, as wasps can be aggressive if you disturb them in a meadow or garden, or even simply while eating outdoors. Bees sting less frequently; hornets are rarer.

How do you tell which insect it is? Unlike bees, wasps and hornets do not lose their stinger when they sting and can do so multiple times; for this reason, it is advisable to move away immediately after being stung. A bee, on the other hand, leaves its stinger in the skin and dies after stinging, because along with the stinger it also loses some glands and abdominal muscles.

Insect bites from mosquitoes and sandflies, however, should not cause concern, as they only result in a swelling of the skin with redness and intense itching, which can vary depending on the person and the insect. Stings from hymenoptera cause, in most cases, a local reaction: red swellings of the skin, of variable size (generally from 2 to 4 cm), with pain, redness, and swelling. This is a normal reaction, due to the venom injected by the hymenopteran, which contains dozens of irritating and toxic chemicals. A local reaction should not be a cause for concern and generally does not require therapy due to its short duration, which can range from a few minutes to a few hours depending on the sting site. Wasp stings can occasionally cause swelling that persists for a few days and causes itching if touched, especially during the night. In this case, it may be useful to consult a specialist for appropriate therapy, usually a topical corticosteroid and an oral antihistamine.

Only a small percentage of people, about 10%, may have more severe systemic reactions, such as nausea and/or vomiting, a drop in blood pressure, and/or widespread hives. In this case, a dermatological examination is essential. In extreme cases, finally, there can be the dreaded anaphylactic shock with a severe reduction in blood pressure that can even lead to death. Typically, there are preceding symptoms such as numbness, loss of consciousness, and even fainting. This clearly represents a medical emergency, after which you must immediately go to the Emergency Room.

How do you know if you are allergic to an insect sting?

An allergy to hymenopteran venom is due to the fact that the person who is stung possesses antibodies against some of the substances present in the venom, which can cause extensive local reactions (over 10 centimeters in diameter) or major reactions such as generalized hives and anaphylactic shock.

How long does a reaction to an insect sting last?

A sting from a bee, wasp, or hornet produces a reaction that rarely lasts more than 30 minutes. The effects of the sting manifest within a few minutes, but in some cases even after an hour. In the case of a true allergy to insect venom, which presents with an extensive reaction, the effect is more severe and long-lasting. The reaction can peak even after 24 hours (but it is not uncommon for the peak to be reached after 48 hours), and the allergic reaction can last from 7 to 10 days.

How to behave, then, in the case of an insect sting?

First of all, it is essential to stay calm, also because, as mentioned, sudden movements could attract other insects or further irritate the one that has already stung, leading to new stings. In the case of a bee sting, which leaves the stinger, it must be removed immediately. The stinger may appear as a small black dot, usually in the center of the red lesion; removing it is essential to prevent the venom from continuing to be injected. In the case of a normal reaction, it is then sufficient to apply ice and not scratch, to avoid bacterial superinfections. If the reaction is extensive, it is prudent to apply a corticosteroid cream and take an oral antihistamine and consult a specialist. In severe cases, of course, alerting the Emergency Room is essential.

Recommendations.

If you plan to go on an outdoor trip and have already had allergic reactions and/or have a family history of anaphylactic shock from insect stings, it is essential to carry emergency medications that your doctor will prescribe, such as injectable adrenaline in pre-filled syringes, which are easy to use. Even in the case of multiple stings (8-10), despite the absence of an allergy, it is advisable to call the Emergency Room, due to the cumulative effect of the injected venom. Furthermore, venom poisoning can cause damage to the heart, kidneys, and muscles.

How to try and prevent stings?

There are some behaviors that represent "good practices":

• When in the presence of insects, stay calm; insects never sting unless in self-defense, so much so that venom is not even used for predation in wasps and hornets.

• Avoid walking barefoot on summer lawns, especially damp ones, as wasps are attracted to water.

• Keep food in containers, so that the smell does not spread and attract insects.

• Bees do not sting far from the hive, but it is still inadvisable to disturb them.