Key takeaways

  • Bug bites can become infected when scratching breaks the skin and introduces bacteria, potentially leading to conditions like impetigo, cellulitis, lymphangitis, or Lyme disease.
  • Warning signs of infection include redness or discoloration, increasing pain, warmth around the bite, pus or fluid drainage, swelling, and streaks extending from the bite area.
  • Most infected bites need antibiotic treatment. Contact a doctor if you have concerns about an infection after a bug bite.

Some bug bites may resolve with home remedies. However, medical treatments may be necessary for some bites, such as:

  • bites from poisonous insect
  • bites that cause a serious condition such as Lyme disease
  • bites or stings from an insect to which you’re allergic
  • bites that become infected

Read on to learn how to identify infected bug bites and how to treat them. This article also looks at when to contact a doctor or seek medical advice for an infected bug bite.

Most bug bites will be itchy for several days. While it may heal with home remedies, it’s important to look out for signs of infection.

An infected bug bite may cause:

View the slideshow below for photos of infected bug bites.

Bug bites can often cause a lot of itching. Scratching may make you feel better, but breaking the skin can transfer bacteria from your hand into the bite. This can lead to an infection.

Different infections can develop following a bug bite.

Impetigo

Impetigo is a skin infection. It’s most common in infants and children, but adults can get it too. Impetigo is very contagious.

Impetigo is more common in itchy bites. It causes sores around the bite. Eventually, the sores rupture, ooze for a few days, and then form a yellowish crust. The sores may be mildly itchy and sore.

The sores may be mild and contained to one area, or more widespread. More severe impetigo may cause scarring.

No matter the severity, impetigo is usually not dangerous and can be treated with antibiotics. However, untreated impetigo can cause cellulitis.

Cellulitis

Cellulitis is a bacterial infection of your skin and the surrounding tissue.

Symptoms of cellulitis include:

  • redness or discoloration that spreads from the bite
  • fever
  • swollen lymph nodes
  • chills
  • pus coming from the bite

You can usually treat cellulitis with antibiotics. Untreated or severe cellulitis can cause sepsis, a life threatening complication of infection.

Lymphangitis

Lymphangitis is an inflammation of the lymphatic vessels, which connect lymph nodes and move lymph throughout your body. These vessels are part of your immune system.

Symptoms of lymphangitis include:

  • irregular red or discolored tender streaks that extend out from the bite, which may be warm to the touch
  • enlarged lymph nodes
  • fever
  • headache
  • chills

Antibiotics can treat lymphangitis. Without treatment, it can lead to complications of infections, such as sepsis.

Lyme disease

Lyme disease is an illness caused by bacteria transmitted through tick bites. In the United States, Lyme disease is most common in the northeast, mid-Atlantic, and north-central states.

  • a bull‘s-eye-shaped rash
  • fever
  • headache
  • joint pain
  • muscle pain
  • fatigue

Lyme disease rashes usually appear within 1 to 4 weeks after the tick has bitten you, though it can take up to 3 months to appear. Not everyone who has Lyme disease gets a bull’s-eye rash, but it’s characteristic of Lyme disease.

Antibiotics can treat Lyme disease. It’s important to diagnose and treat Lyme disease early, and you should always check for ticks after being outdoors in areas where Lyme disease is common.

Untreated Lyme disease can cause issues with your joints, heart, and nervous system.

You may be able to treat minor infections at home with over-the-counter (OTC) antibiotic ointments. In many cases though, you’ll need to contact a doctor if you have an infected bug bite or sting.

You should contact a doctor if:

  • you have signs of a systemic infection, such as chills or a fever
  • a child has any signs of an infected bug bite
  • you have signs of lymphangitis, such as streaks extending from the bite
  • you develop sores or abscesses on or around the bite
  • the pain on or around the bite gets worse over a few days after you’ve been bitten
  • the infection doesn’t get better after using an antibiotic ointment
  • redness or discoloration spreads from the bite and gets bigger

Other reasons to contact a doctor

An infection is just one reason to contact a doctor after an insect bite or sting. You should also contact a doctor after a bite or sting if you:

  • are stung or bitten in the mouth, nose, or throat
  • have flu-like symptoms a few days after a tick or mosquito bite
  • have a rash after a tick bite
  • are bitten by a spider and have any of the following symptoms within around 8 hours:
    • cramping
    • fever
    • nausea
    • severe pain
    • an ulcer at the site of the bite

Additionally, get emergency medical treatment if you have symptoms of anaphylaxis, an emergency condition caused by a severe allergic reaction.

Anaphylaxis is a severe reaction to a trigger, such as an allergy, and is potentially life threatening.

Symptoms can develop quickly and include:

  • feeling faint or lightheaded
  • difficulty breathing or wheezing
  • rapid heartbeat
  • confusion
  • anxiety
  • clammy skin
  • collapsing or losing consciousness
  • hives
  • swelling
  • stomach pain, nausea, or vomiting

If you or someone nearby develops these symptoms, you should:

  1. Check to see whether they have an epinephrine pen. If they do, read and follow the instructions to dispense the medication.
  2. Dial 911 (or a local emergency number).
  3. Lay them down. If they have vomited, lay them on their side.
  4. Stay with them until emergency services arrive.

It is possible for someone to need more than one injection with an epinephrine pen. If symptoms do not begin to clear after 5 minutes, give a second injection if one is available.

A doctor can advise on medical treatments to treat an infected bite or sting. The treatment may depend on the type of infection that develops.

Your doctor may recommend a combination of medical treatments and home remedies.

Home remedies

Most home remedies focus on easing symptoms while you’re taking antibiotics.

Home remedies for infected insect bites can include:

  • cleaning the bite with soap and water
  • keeping the bite and any other infected areas covered
  • using ice packs to reduce swelling
  • using topical hydrocortisone ointment or cream to reduce itching and swelling
  • taking an antihistamine such as Benadryl to reduce itching and swelling
  • taking pain relief medication such as ibuprofen to manage pain

Medical treatments

In many cases, an infected bug bite will need an antibiotic. You may be able to try OTC antibiotic ointments for minor bug bites without symptoms of severe infection. Your pharmacist can recommend the right ointment for you.

If symptoms do not improve, or if your infection is severe, a doctor can prescribe stronger topical or oral antibiotics.

If abscesses develop because of the infection, it may be necessary to drain it. This is usually an outpatient procedure.

It can be hard to prevent bug bites if you spend time outside, but there are some steps you can take to make it less likely that you get bitten.

Tips for reducing the likelihood of bug bites include:

  • using insect repellent when you’re outside, especially repellents that contain DEET
    • Be sure to test them on a small patch of skin first to make sure they don’t irritate you.
  • wearing long sleeves and pants whenever possible.
  • avoiding standing water and humid but shady areas, as types of places attract mosquitoes
  • staying calm and back away slowly if a bug is near you
  • checking your body for ticks after returning from tick-infested areas, and removing any ticks immediately.

Scratching a bug bite may make you feel better, but it can also cause an infection if bacteria from your hand gets into the bite.

Types of bug bite infections can include impetigo, cellulitis, lymphangitis, and Lyme disease. They can cause symptoms such as redness or discoloration, swelling, warmth, and pus.

Contact a doctor as soon as you have concerns about an infected bug bite. Your doctor may recommend OTC or prescription antibiotics. Some home remedies, such as applying an ice pack and taking pain relief medication, may also help manage symptoms.