<Things you should know> Correct knowledge about insect bites (1) Explanation of the causes and symptoms of "insect bites" What is an insect bite? Insect bite symptoms Things to be aware of regarding insect bites (severe symptoms) How insect bites work Causes of insect bites Insect bites can lead to various skin problems, including itching and pain. Depending on the symptoms and the type of insect, it may be necessary to see a doctor immediately, so it's important to have the correct knowledge about insect bites. This article provides a detailed explanation of the common causes and symptoms of insect bites. What is an insect bite? Insect bites are sometimes called "insect bite syndrome." It is a common skin condition, and the symptoms are thought to be caused by an "irritant reaction" or "allergic reaction" to the insect's venom or other components. The way symptoms manifest varies greatly from person to person and depends on factors such as age, the amount of venom released, and the severity of the allergic reaction. While various insects can cause bites, common examples include blood-sucking insects such as mosquitoes, black flies, horseflies, fleas, and bed bugs; insects that sting the skin such as bees; and insects that bite the skin such as spiders and centipedes. Additionally, poisonous caterpillars can cause dermatitis upon contact. This article will explain common insect bites that can occur in daily life. Insect bite symptoms Allergic reactions to insect bites can be broadly divided into two types: "immediate reactions," which occur immediately after being bitten, and "delayed reactions," which occur one to two days later. In immediate-type reactions, itching, redness, and hives appear immediately after being bitten by an insect, while in delayed-type reactions, itching, redness, bumps, and blisters appear 1 to 2 days later. Although there are individual differences, symptoms of immediate-type reactions subside within a few hours, while symptoms of delayed-type reactions lessen within a few days to a week. Let's take a closer look at the main symptoms you might experience from insect bites. itch This is one of the symptoms that often occurs immediately after being bitten or touched by an insect. It is caused by an allergic reaction to the venom or salivary gland substances injected into the skin. Severe scratching can damage the skin and may lead to hyperpigmentation. pain Pain can be caused not only by insect bites or stings, but also by chemical irritation from substances that insects inject into the skin. swelling A part of the skin may become red and swollen. For example, a black fly bite will cause redness, swelling, and intense itching, while a bee bite will cause swelling along with intense pain. redness This symptom is also called redness or erythema. The skin becomes red due to inflammation. The redness may appear immediately or 1-2 days after contact with the insect. wheal A condition where a part of the skin becomes red and raised. The edges are clearly defined, and it is accompanied by itching. blisters Sometimes, blisters can form some time after an insect bite. Be careful not to scratch them, as this can cause the affected area to spread and worsen. lump When bitten by a black fly (black fly, gnat), symptoms such as swelling and severe itching may appear about half a day later, and in some cases, a red lump may remain for a long time. Insect bites Things to be careful about(Severe symptoms) If it's a mild insect bite, the symptoms will subside after a few hours, so there's no need to worry too much. However, some insect bites can cause symptoms not only at the bite site but throughout the entire body, so caution is necessary. Of particular concern are insect bites, such as those from bees, which can cause anaphylactic shock. Although there are individual differences, symptoms such as a drop in blood pressure, difficulty breathing, and loss of consciousness can occur 30 minutes to an hour after being bitten, and in some cases, it can be life-threatening. Furthermore, it is said that being bitten by a venomous spider such as the redback spider can cause not only local pain but also systemic symptoms such as muscle pain, nausea, and headaches. How insect bites work Even though we refer to them simply as "insect bites," the mechanisms that cause symptoms differ depending on the type of insect. For example, with blood-sucking insects like mosquitoes, it's thought that an allergic reaction to the substance injected during blood-feeding can occur, leading to a variety of symptoms. Alternatively, with insects that sting or bite the skin, the irritation can lead to pain. Additionally, some types of caterpillars have poisonous hairs, and contact with them can cause symptoms such as severe itching, pain, redness, and small blisters. Causes of insect bites The following are some insects that can cause skin symptoms from insect bites: Mosquito They can be found anywhere, including inside houses, gardens, parks, and fields. Exposed areas such as the face and limbs are most often bitten. When they land on the skin and suck blood, symptoms such as itching and redness appear. Dust mites Indoors, many cases involve damage caused by house dust mites, which parasitize mice. These mites are small, about 0.7 mm in size, and often bite people without them realizing it, as they feed on blood while people are sleeping. The sides of the torso, lower abdomen, and inner thighs are common areas of bite, and symptoms include intense itching and red bumps.Additionally, there are cases of people being bitten by ticks in the wild. Ticks bite human skin and suck blood, but if you try to forcibly remove them, the tick's mouthparts may remain in the skin and cause infection, so you should see a dermatologist immediately. Black fly (gnat, black fly) This blood-sucking insect resembles a fly and is commonly found along streams in highlands and mountainous areas. Usually, there are few immediate symptoms after being bitten; it takes about half a day for the bite site to become red, swollen, and intensely itchy. A red lump may also remain for a long time. flea Most cases of bites are caused by cat fleas, which infest cats and dogs. Outdoors, they jump up from the ground, so bites are common on the shins and legs, but indoors, bites can also occur on the arms and body. They are blood-sucking insects, and some people only realize they've been bitten when symptoms such as red bumps and itchiness appear 1-2 days after they've sucked blood. Blisters can also form. Bee Stings by paper wasps and hornets are common during activities such as gardening, farming, and hiking. Be especially careful during autumn outdoor activities, as the number of incidents is particularly high. A sting causes intense pain and redness due to the effects of the wasp venom.If it's your first time being stung, the symptoms usually subside within a day. However, after the first sting, an allergic reaction to the bee venom may cause hives, severe redness, swelling, and other symptoms. There is also a possibility of anaphylactic shock, which can lead to a drop in blood pressure and loss of consciousness, so it is important to carefully monitor your condition. caterpillar Not all caterpillars are poisonous; touching caterpillars with venomous hairs, such as those of the gypsy moths and stinging nettle caterpillars, can cause skin symptoms such as pain and redness.Touching poisonous moths can cause intense itching and red bumps to appear, concentrated on the neck and arms, and scratching can spread the symptoms to the surrounding area.Touching a stinging caterpillar (Limacodidae) immediately causes a sharp, stinging pain and redness. The symptoms usually subside within 1-2 hours, but swelling and itching may appear the next day. We take care to post accurate information,Please point out any incorrect information. Please submit any comments regarding medical information here. Return to the list of guides categorized by health symptoms.