- Insect Bite Symptoms
- What Is a Spider Bite?
- What Is a Mosquito Bite?
- Types of Spider Bites
- Complications and Side Effects
If you have an insect bite, you’ll often notice some redness and itching in the spot where you were bitten. If you’re not sure what kind of bug caused the bite, you may not know how to best treat the symptoms. There are some ways to tell the difference between a spider bite and mosquito bite and some clues for when you should seek medical care.
What is a spider bite?
Spiders are not technically insects. They are arachnids which are a class of arthropods that also includes scorpions, mites, and ticks. There are more than 45,000 known species of spiders around the globe and around 3,500 kinds in the United States. Around 50 of those have venom and can bite humans. Spiders have tiny fangs. When they bite, the fangs puncture your skin and inject venom. All of the symptoms related to spider bites are your body reacting to the venom.
The majority of spiders in the United States are not dangerous to humans. Spiders also not are usually aggressive. The majority of bites happen when the spider is trapped or accidentally contacted.
Most spider bites cause minimal symptoms — like a red spot with some itchiness — and go away on their own within a week. There are a few kinds, however, that can be dangerous and require a doctor’s care. Venomous spiders in the United States include the black widow and brown recluse spiders.
What is a mosquito bite?
Mosquitoes, unlike spiders, are actual insects. They puncture your skin with their long funnel-like mouth to draw up blood. Your skin reacts with some redness, swelling, and itching in the spot where it is punctured. While the actual bites from mosquitoes are not dangerous, they can transmit lethal diseases like malaria, yellow fever, and dengue.
There are a few ways to determine whether you have a spider bite rather than a mosquito bite. Generally speaking, mosquito bites cause some irritation and discomfort but resolve on their own within a couple of days. Rare instances of serious reactions have occurred, but they are very infrequent.
Symptoms of a mosquito bite include:
- A puffy, red bump appearing minutes after the bite
- A firm, red or brown bump in the days following the bite
- Localized swelling
Any bite that does not begin to resolve itself or seems to be getting worse should be examined by your doctor.
Types of spider bites
Non-dangerous spider bites
Most spider bites are irritating but not dangerous to humans. They usually last a day or two and are entirely resolved within a week. The symptoms of a non-dangerous spider bite include:
- Redness at the spot of bite, typically smaller than a quarter
- Swelling and tenderness
- Pain that can feel similar to a bee sting
The brown recluse spider (Loxosceles reclusa), also known as the “fiddle back spider” or the “violin spider” because of its markings, tends to live in undisturbed places like closets or attics. Bites can range from mild to serious.
Symptoms of a brown recluse bite can include:
- Redness followed by a blister at the site of bite
- Mild to intense pain and itching for two to eight hours
- An open sore with tissue breakdown developing a week or more after the bite
- Fever and chills
- Tiny, flat red and purple spots all over your body
- Nausea and vomiting
- Joint pain
The black widow spider (Latrodectus mactans) is an all-black spider except for the red or orange hourglass marking on its abdomen. A shy spider, the black widow only bites when threatened.
Many black widow bites cause only a moment of pain and some redness that resolves within a few days. However, some people may have a more severe reaction and require medical care. Symptoms of a black widow bite can include:
Diagnosis for spider bites
If possible, try and capture the spider that bit you. Bringing the actual spider will help your doctor quickly identify the type of spider it is and how to treat it.
Without the offending spider’s presence, your doctor will gather information about when and where you sustained the bite. Your doctor will also examine the bite to determine what the symptoms indicate.
Treatments for insect bites
If you receive an insect bite — either a spider bite or mosquito bite — there are some ways to manage the irritation and discomfort at home:
- Wash the area with mild soap and water
- Place an ice pack or cold compress on the bite
- Use over-the-counter pain relievers to manage discomfort
- Apply a topical steroid like hydrocortisone or an antihistamine for itching
Your doctor can use specific medication to counteract the effect of specific spider venom — black widow or brown recluse — and to ensure that you do not suffer any complications. This may include antibiotics to prevent a secondary infection. If you believe that one of these spiders is responsible for your bite, you should try to safely collect the spider and seek care right away.
Possible complications and side effects of insect bites
The vast majority of spider bites and mosquito bites cause minor irritation and go away within a few days. However, if you are bitten by a black widow or brown recluse spider, the complications can be serious. Untreated venomous spider bites can cause:
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American Academy of Allergy Asthma and Immunology: "Take a Bite Out of Mosquito Stings."
American Academy of Family Physicians: "Common Spider Bites."
American Osteopathic College of Dermatology: "Spider Bites."
Centers for Disease Control and Prevention: "Mosquito Bite Symptoms and Treatment."
Childrens MD: "Signs and Symptoms of a Brown Recluse Spider Bite."
Fairview: "Black Widow Spider Bite."
National Geographic: "Mosquitoes."
National Geographic: "Spiders."
The National Institute for Occupational Safety and Health: "Venomous Spiders."
Seattle Children’s Hospital: "Spider Bite."
Stanford Children’s Health: "Spider Bites."
UC Riverside Department of Entomology Spider Research: "Not Recluse."
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Home Remedies for Mosquito BitesMosquito bites appear as red, itchy rashes, which resolves in a few days. A few mosquitoes act as a vector to spread diseases like Malaria, West Nile virus, Yellow fever, Dengue, Chikungunya, Encephalitis (brain infection), and Zika virus.
How Do You Stop Mosquito Bites From Itching?Mosquito bites can be irritating. Learn what causes the itch and how to stop it.
Is a Banana Spider Bite Poisonous?The banana spider is also known as the calico spider, golden silk spider, giant wood spider, Brazilian wandering spider or armed spider. Banana spiders do bite humans and they are poisonous.
What to Know About Spider Bites: Identification and SymptomsThere are many species of spiders around the world such as the jumping spider, wolf spider, brown recluse, black widow, hobo spider, tarantulas, false black widow, camel spider, etc. Most spiders don’t bite unless they are threatened. If you are bitten, take a photo of the spider or take the spider (even dead) to the doctor to help identify it and correlate it with your symptoms.
Spider Bites (Black Widow and Brown Recluse)
Most spiders in the United States are harmless; however, black widow and brown recluse spider bites may need medical treatment. Symptoms of a harmless spider bite generally include pain, redness, and irritation.
Signs and symptoms of black widow spider bite include pain immediately, redness, burning, and swelling at the site of the bite. Sometimes the person will feel a pinprick or double fang marks.
Brown recluse spider bite symptoms and signs are a mild sting, followed by severe pain and local redness. These symptoms usually develop within eight hours or more after the bite. Black widow and brown recluse spider bites have similar symptoms, for example, nausea, vomiting, fever, headache, and abdominal or joint pain.
Generally, brown recluse and black widow spider bites need immediate medical treatment. If you think that you or someone you know has been bitten by a brown recluse or black widow spider, go to your nearest Urgent Care or Emergency Department for medical treatment.
What Do Spider Bites Look Like?The appearance of a spider bite varies depending on the type of spider causing the bite. Spider bites often take longer to heal than other insect bites.
When Should You Go To the Doctor for a Spider Bite?Learn what medical treatments can help with your spider bite symptoms and speed up your spider bite recovery.