Insect Allergies

Insect and spider bites often cause minor swelling, redness, pain, and itching. These mild reactions are common and may last from a few hours to a few days. Home treatment is often all that is needed to relieve the symptoms of a mild reaction to common stinging or biting insects and spiders.

Some people have more severe reactions to bites or stings. Babies and children may be more affected by bites or stings than adults.

Many insects, including the following, cause mild to more serious reactions:

• Bedbugs—flat, wingless insects about 0.6 cm (0.25 in.) long, ranging in colour from almost white to brown. They turn rusty red after feeding. Like mosquitoes, bedbugs feed on blood from animals or people and can cause skin irritations. Bedbugs have that name because they like to hide in bedding and mattresses. They usually hide during the day and are active at night when they feed. They can go for weeks without feeding. They are found worldwide.
• Chiggers—tiny mites that live in areas with grass or brush, also known as red bugs or harvest mites, usually cannot be seen without a magnifying glass. Chiggers attach to skin pores and feed on skin cells for a few days, most often in the warm creases of the body. In the United States chiggers do not cause any diseases. Some types of chiggers in Asia and the Pacific carry a disease called scrub typhus. Chigger bites can result in: intense itching at the bite site, beginning a few hours after the bite and may be at its worst on the second day–perhaps lasting for days or weeks; a raised bump that gets bigger over twenty-four to forty-eight hours and may be present for up to 14 days. Less commonly, fever and a rash. Home treatment can help relieve itching. The mites will fall off the body within a few days.
• Fleas—small, wingless parasitic insects that have a hard, shiny surface and travel by jumping. Flea bites usually cause only mild symptoms in humans that can be relieved by home treatment measures, such as non-prescription cortisone cream. Signs and symptoms of flea bites may include: zigzag lines, especially on the feet and legs and in the waist areas. intense itching; a single hive or wheal; dull red spots that last even after other symptoms disappear; blisters or open sores in highly sensitive people. Adult fleas may live in floor crevices, debris, and carpeting for years and can survive for months without feeding. In rare cases, they can carry disease, such as plague. Destroying household fleas (extermination) is an important part of treatment.
• Flies—there are over fifteen thousand species of flies in North America. Some of the most common domestic fly species in Canada include blow/bottle flies, cluster flies, drain flies, fruit flies, flesh flies, phorid flies, and house flies. Flies always live close to suitable food sources and breeding grounds. In homes, they look for warm, moist, decaying organic matter. Although not all flies bite, those that do can be an irritation and danger to some people. Examples of reactions range from small, itchy, red patches to swelling, bleeding, and lymph node swelling. If your symptoms are severe, consult a medical professional.
• Kissing bugs—winged insects that are about 2 cm (0.75 in.) long, dark brown or black with red or orange spots along the edge of their bodies. Also called assassin bugs or cone-nosed bugs. Like mosquitoes, kissing bugs feed on blood from animals or people. Kissing bugs have that name because their bites are often found around the mouth. They usually hide during the day and are active at night when they feed. They can go for weeks without feeding. Found in the warm southern states of the U.S. and in Mexico, Central America, and South America.
• Lice (including Body Lice, Head Lice, and Pubic Lice)—tiny insects that live on the human body or clothes, and feed on our blood. 
  Body lice are tiny insects that can make a temporary home in the seams of your clothing or bedding (sheets, pillows, and blankets). They’re most often spread by contact with a person who has body lice or with that person’s clothes, bedding, or towels. Body lice are usually found only among people who can’t wash their bodies or their clothes regularly. Symptoms include: itching, especially at night, and sores in the armpits, waist of torso.
  Head Lice are tiny insects that live close to the scalp where they lay and attach their eggs. Lice can live a month on the head. But they can only survive 1 to 2 days without the warmth of a person’s head. And they can’t hop or jump. It’s common to get lice from direct contact with someone’s head. It’s not common to get lice from a bed, pillow, couch, or carpet. Getting lice can be inconvenient but lice aren’t dangerous, and they don’t spread disease or have anything to do with how clean someone is. And you can learn how to treat lice at home.
  Pubic lice are tiny insects that usually live in your pubic area. Sometimes they’re also found on facial hair, eyelashes, eyebrows, armpits, and chest hair. They’re different than the kind of lice that you can get on your head. Pubic lice are also called “crabs” because they look like tiny crabs. Millions of people get pubic lice every year. It doesn’t mean you’re not clean. Pubic lice are usually spread through sexual contact. But sometimes they can spread through shared clothes, bedding, or towels. It’s rare to get pubic lice from a toilet seat. That’s because lice can’t live more than a day or two away from a human body. Pubic lice can be uncomfortable and inconvenient, but they’re not dangerous. It is important to receive treatment as soon as possible.
• Mites—belong to the family (arachnid) that includes spiders, ticks, and scorpions, but mites are barely visible with the naked eye. Some mites are parasites that live on humans or other animals and may cause diseases such as typhus, scabies, and mange.
• Mosquitoes—blood-sucking insects attracted to moisture, sweat, heat, and carbon dioxide. They are attracted to some people more than others. Mosquitoes most often feed from dusk to dawn. They carry disease in some parts of the world. They are carriers of the West Nile virus and may transmit the virus to humans and animals. West Nile virus causes an infection that can lead to inflammation of the brain (encephalitis) or the tissues surrounding it and the spinal cord (meningitis). Mosquitoes in Africa as well as other parts of the world may carry malaria or yellow fever. Mosquitoes do not carry the human immunodeficiency virus (HIV). Symptoms of a mosquito bite may last for hours, days, or even weeks. Common symptoms that begin immediately are: reddened skin, a swollen lump (wheal), and itching. Staying indoors at dawn and dusk and in the early evening, coupled with wearing long-sleeved shirts and long pants when outdoors, may lower the risk for mosquito bites. Insect repellent, applied sparingly to skin and sprayed on clothing, may keep mosquitoes away.
• Non-poisonous spiders—symptoms of a non-poisonous spider bite may last from a few hours to a few days and are usually mild. Symptoms usually occur at the site of the bite and may include: swelling, redness, pain, itching. Home treatment is often all that is needed to prevent infection and relieve symptoms of a bite from a non-poisonous spider.
• Scabies—an itchy skin condition caused by tiny mites that burrow into the outer layers of the skin. The scabies mites are spread through close contact with an infested person, such as by touching or by sleeping in the same bed. Severe itching, usually worse at night, and a rash with tiny blisters or sores in a line or curved track are the most common symptoms. These symptoms usually occur between the fingers, in the creases of the elbows or in the armpits, around the waistline, on the genitals, and around the anus. In children, signs of scabies may also appear on the neck, face, scalp, the palms of the hands, or the soles of the feet. Scabies can be spread during the entire time a person is infested, even before symptoms, such as itching and skin sores, appear. Symptoms appear four to six weeks after a person has been infested for the first time. If a person becomes re-infested, the symptoms are noticed within a few days. Scabies will not go away on its own. It is usually treated with a non-prescription cream or lotion that your doctor or medical practitioner recommends. You may need a prescription medicine if your scabies does not go away with over-the-counter treatment. Delaying treatment increases the risk that the mites will spread to other people. Bedding, towels, and clothes that have been in contact with the infested person need to be washed.
• Ticks—small, blood-sucking bugs ranging in size from as small as a pin’s head to as large as a pencil eraser. They have eight legs and are arachnids, which means they’re related to spiders. Different kinds of ticks can range in color from shades of brown to reddish brown and black. Unlike most other bugs that bit, ticks typically remain attached to your body after they bite you. As they take in more blood, ticks grow. At their largest, ticks can be about the size of a marble. After a tick has been feeding on its host for several days (up to ten days), they become engorged and can turn a greenish-blue color. Tick bites are fairly common in North America as they live outdoors in grass, tress, shrubs, and leaf piles. Tick bites are often harmless, in which case they don’t cause any noticeable symptoms. However, ticks can cause allergic reactions, and certain ticks can pass diseases onto humans and pets when they bite. These can be dangerous or even deadly. Typical symptoms of tick bites range from pain or swelling at the bite site, a rash, a burning sensation at the bite site, to blisters, etc. If you have an allergic reaction to a tick bite it can also include neck stiffness, headache, nausea, muscle or joint pain or achiness, fever, chills, swollen lymph nodes, or difficulty breathing. Be sure to seek medical attention as soon as possible when bitten by a tick. Special Note: While most tick bites are harmless, there is a zero to fifty percent chance of odds of contracting Lyme Disease from a tick bite. The sooner you can safely remove a tick from your body and have it tested for tick-borne disease the better. To safely remove a tick bite, you might want to check out this link from Firelands.com https://www.firelands.com/blog/keep-lookout-symptoms-tick-bite-summer. If you experience the more severe reactions to a tick bite, please consult a Lyme Disease specialist to get an assessment.

Some insects are more likely than others to cause allergic or toxic reactions.

• A bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called killer bees, are more aggressive than common honeybees and often attack together in great numbers. Reaction to bee stings can range from minor skin swelling and redness to a serious allergic reaction.
• A fire ant (wingless insects belonging to the same family as bees and wasps and typically found in the southeastern and south-central United States, especially along the Gulf Coast)) attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its abdomen in a circular pattern at multiple sites. They tend to attack and sting in great numbers. Symptoms may include: a painful raised bump that becomes a pus-filled blister in six to twenty-four hours and lasts for up to ten days; skin at the bite site that dies and leaves a scar or bump. If you have a toxic reaction or receive twenty or more stings, your should seek treatment from a medical practitioner immediately.
• Wasps, including hornets and yellow jackets, can sting over and over. Yellow jackets cause the greatest number of allergic reactions.

Bites and stings are more serious and you should seek immediate medical attention if you develop one or more of the following conditions after an insect or spider bite or sting:

• A severe allergic reaction or anaphylaxis—
  Skin: hives, swelling of face, lips, tongue, itching, warmth, redness;
  respiratory (breathing): coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing;
  Gastrointestinal (stomach): nausea, pain or cramps, vomiting, diarrhea;
  Cardiovascular (heart): paler than normal skin colour/blue colour, weak pulse, passing out, dizziness or lightheadedness, shock; or
  Other: anxiety, sense of doom (the feeling that something bad is about to happen), headache, uterine cramps, metallic taste
• A toxic reaction—occurs when insect or spider venom acts like a poison in the body. This type of reaction can occur from one bite or sting from a highly toxic insect or spider, or from multiple bites or stings from insects or spiders not normally considered poisonous. A toxic reaction may require immediate medical care or may lead to death. Signs and symptoms of a toxic reaction may include: nausea or vomiting, diarrhea, fever, weakness, light-headedness, rapid swelling at the site of the bite or sting, muscle spasms, headache, drowsiness, fainting, or infection.
• A large skin reaction with swelling and redness that spreads away from the site of the bite or sting. It may be as large as swelling across two major joints, such as from the elbow to the shoulder.
• Signs of a skin infection—can develop after an injury or wound to the skin or the mucous membranes, such as the inside of the mouth or nose. Symptoms of infection may include: increased pain, swelling, warmth, or redness in or around the area; red streaks leading from the area; pus draining from the area; a fever.
• Serum sickness—an unusual reaction to any foreign substance in the body. Venom from insect stings or spider bites and medicines such as penicillin are common causes of this reaction. Symptoms of serum sickness usually begin between seven to ten days after the person is exposed to the substance. A person usually feels generally unwell (malaise) and may have hives, joint pain, fever, headache, and swollen glands. Having an episode of serum sickness puts a person at high risk for developing a severe allergic reaction if they are exposed to the same substance in the future. A person should avoid any medicine related to serum sickness after it has been identified. Venom immunotherapy may be an option to protect against insect or spider bites that caused the reaction.

(Sourced from: HealthLink BC, Medical News Today, My Health Alberta, Healthline, Healthwise)