Insect Bite Treatment

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Infected Insect Bite

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Before you start a diagnosis, please read all of the information below.

An insect bite or sting will usually cause a swollen red area to develop on the skin. Most will settle on their own accord within a few hours or days. The severity of bites and stings will differ depending on the type of insect causing it and the sensitivity of the person. 

Sometimes the insect bite can become infected with bacteria. An infection may occur if you scratch an insect bite, or it may be introduced into the skin at the time you are bitten. You may develop symptoms of a wound infection, such as pus or increasing pain, swelling or redness. Infections are usually treated with antibiotics.

Please see the 'Common Treatments' section below for further information.

Examples of insects that may bite or sting include wasps, hornets, bees, horseflies, ticks, mosquitoes, fleas, spiders, midges, and bedbugs.

Some people may develop a mild allergic reaction to the bite or sting. This will usually cause a larger area or redness to develop.

Occasionally a more severe allergic reaction (anaphylaxis) can occur. This may cause swelling of the face, lips or tongue, dizziness, difficulty in breathing or fainting. This is a medical emergency and requires immediate medical attention. Call 999 if you suspect a medical emergency.


Common Symptoms

The following are possible symptoms you may experience if your insect bite becomes infected:

  • red swollen area of skin
  • itching around the area
  • pain and tenderness affecting the area
  • fluid filled blisters
  • weals - circular, fluid-filled areas surrounding the bite
  • hot skin
  • pus discharging from the wound
  • feeling unwell
  • fever
  • swollen glands
Common Treatments

Speak to your pharmacist for advice on over the counter treatments that may help such as anti-histamines, creams and painkillers.

If your insect bite becomes infected then you may require antibiotics.

Possible treatments we prescribe if clinically appropriate:


*Prices shown are cost price of the medication, taken from the British National Formulary 2018, and are given as a guideline. Pharmacies will add a dispensing fee to this which will vary considerably, so it is worthwhile phoning around to compare prices. The medication is paid for at your chosen pharmacy. 

Please click on the medication above to read the Patient Information Leaflet for important information about each drug. We use national prescribing guidelines to select which treatment would be most appropriate for your condition. 

Self-help for the symptoms

To treat an insect bite or sting:

  • If there is a sting or tick still in the skin, then remove this.
  • Wash the affected area with soap and water.
  • Apply a cold compress or an ice pack to the area for at least 10 minutes.
  • If possible, elevate the affected area as this can help improve any swelling.
  • Wash your hand before touching the area and avoid scratching it to reduce the risk of infection.
  • Use a cream or spray that contains a local anaesthetic, antihistamine or mild steroid (hydrocortisone 1%) on the affected area to help reduce itching and swelling. Your pharmacist can advise on this.
  • Take an antihistamine tablet to help reduce swelling. Please read the information leaflet contained with the medication to check it's suitability.
  • If the area is painful then take painkillers, such as paracetamol or ibuprofen. Please read the information leaflet contained with the medication to check it's suitability or speak to your pharmacist if you are unsure.
Risk factors

You're more likely to be bitten or stung if you work outdoors or regularly take part in outdoor activities, such as camping or hiking. Risk factors include:

  • large areas of exposed skin
  • dark clothing
  • eating outside
  • exposure to hives or nests
  • floral perfume
  • loose clothing
  • participating in outdoor recreation
  • working outside
Allergic Reactions

An itchy rash, swollen face or mouth, or difficulty in breathing, may be signs that you are allergic to the insect bite or the medication. 

Please note that i-GP DOES NOT TREAT Medical Emergencies. For Medical Emergencies please call 999.

If you develop a sudden onset of any of the symptoms below then you must STOP the medication immediately and seek urgent medical advice. This could be from your GP, Out of Hours Service, Urgent Care Centre or NHS 111. Call an ambulance using 999 or go to A&E if the symptoms are severe.

  • wheeze
  • difficulty in Breathing
  • swelling of the eyelids, face or lips
  • a rash particularly if affecting your entire body
  • drowsiness or confusion
  • dizziness or feeling faint
  • chest pain or a fast heart rate
Information about flucloxacillin

The antibiotic Flucloxacillin can be used to treat an infected insect bite if you are not allergic to penicillins. Before you start treatment, always read the manufacturers leaflet contained with the medication. This contains more information and lists all the potential side effects.

The dose is to be taken four times a day, it is important that you space out the doses evenly during the day. Swallow the capsule with water, and take it on an empty stomach. This means an hour before food or 2 hours after food. 

Do not take Flucloxacillin if you are allergic to Penicillin.

Keep taking Flucloxacillin until the full course is finished (unless a doctor tells you to stop), even if you feel that the infection has cleared up. This is to stop the infection from coming back. If you forget to take a dose, take one as soon as you remember unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose as normal.

Never give your medication to other people even if their condition appears to be the same as yours.

Possible side effects to flucloxacillin

Most types of medicines can cause potential side effects. However, not everyone will experience them. The side effects often improve as your body adjusts to the new medicine, but if any of them continue or become troublesome then speak with your doctor or pharmacist. 

The most common ones for Flucloxacillin include:

  • feeling sick (nausea) or vomiting
  • diarrhoea
  • redness and itching in the mouth or genital area (thrush)
  • a skin rash
Information about clarithromycin

The antibiotic Clarithromycin can be used to treat an infected insect bite if you are allergic to penicillins. Before you start treatment always read the manufacturers leaflet contained with the medication, which contains more information and the potential side effects.

The dose is to be taken twice a day; it is important that you space out the doses evenly during the day. Swallow the tablet with water, and you can take Clarithromycin either before or after your meals.

Keep taking Clarithromycin until the full course is finished (unless a doctor tells you to stop), even if you feel that the infection has cleared up. This is to stop the infection from coming back. If you forget to take a dose, take one as soon as you remember unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose as normal.

Never give your medication to other people even if their condition appears to be the same as yours.

Possible side effects to clarithromycin

Most types of medicines can cause potential side effects. However, not everyone will experience them. The side effects often improve as your body adjusts to the new medicine, but if any of them continue or become troublesome then contact us, or speak with your doctor or pharmacist. 

The most common ones (occur in about 1 in 10 people) for Clarithromycin include:

  • feeling sick (nausea) or vomiting
  • diarrhoea
  • redness and itching in the mouth or vagina (thrush)
  • tooth or tongue discolouration, and changes in the way things taste or smell. This will settle once you finish treatment.
  • a headache
Who should not take Clarithromycin

It is important that you tell your doctor in your assessment of all the medical conditions you have, and all the medications you take. Failure to do so can lead to problems with any treatment you are prescribed. Always read the patient leaflet before you take any medication. 

The following groups of people should not take Clarithromycin:

  • those allergic to clarithromycin or macrolide antibiotics
  • those with QT prolongation or ventricular cardiac arrhythmia, including torsades de pointe
  • those with heart disease
  • those with hypokalaemia (low potassium)
  • those with problems with the way your liver works
  • pregnant women or if breastfeeding 

The following medications can interact with Clarithromycin:

  • Statin for lowering cholesterol: you should stop your statin while you are taking Clarithromycin.
  • Colchicine used for gout: clarithromycin should not be taken if you are also taking colchicine. 
  • Warfarin: Clarithromycin can increase the bleeding risk
  • Ergotamine or dihydroergotamine used for migraines: Clarithromycin must not be taken with them
  • Sildenafil, tadalafil or vardenafil: Clarithromycin can increase the levels of the erectile dysfunction (ED) medication in the body. Consider reducing the dose of the ED medication while taking Clarithromycin. 
When to seek further medical advice

If you develop any of the following symptoms, then it is important to seek medical advice as soon as possible:

  • If you develop a persistent high fever (high temperature) which can cause shivers.
  • If the pain becomes worse.
  • If you feel increasingly unwell (this may include nausea and vomiting).
  • If you develop spreading redness affecting your skin around the site of your infection.
  • If you develop any painful, red and hot joints near to the infection.

If you develop any of the following symptoms, then you must seek urgent medical advice immediately (from your GP, Out of Hours Service, Urgent care centre, NHS 111). Call an ambulance using 999 or go to A&E if the symptoms are severe.

  • drowsiness or confusion
  • difficulty in breathing or shortness of breath
  • a severe headache
  • if you develop redness, swelling and warmth around the eye
  • if you are unable to look at bright lights (photophobia)
  • chest pain
  • persistent vomiting
  • neck stiffness
  • non-blanching rash
Complications

The most common complications of an insect bite are secondary bacterial infections. This can include the following:

  • impetigo - a very contagious bacterial infection that causes sores, crusting or blisters.
  • cellulitis - a skin infection that makes your skin red, hot, swollen and painful.
  • folliculitis - inflammation of your hair follicles.
  • lymphangitis - an infection that causes red streaks in your armpit or groin and swollen lymph nodes.

Other complications include:

  • Lyme disease: caused by tick bites
  • Malaria: caused by mosquito bites
Malaria

Please be aware that mosquito bites in certain areas of tropical countries can cause malaria. If you have had an insect bite while abroad in an at-risk area and develop any of the symptoms below, then it is important to see a doctor straight away for further tests.

  • a high temperature (fever)
  • sweats and chills
  • headaches
  • vomiting
  • diarrhoea
  • muscle pains

Symptoms usually start between seven and eighteen days after being bitten by a mosquito, but in some cases, the symptoms may not appear for up to a year, or occasionally even longer. A blood test can determine whether you have malaria or not. 

Malaria is found in mainly tropical regions including:

  • large areas of Africa and Asia
  • Central and South America
  • Haiti and the Dominican Republic
  • parts of the Middle East
  • some Pacific islands

Please check the Fit for Travel website for country-specific information about Malaria and advice on anti-malaria medication before travel. 

Preventing insect bites

There are some precautions that you can take to reduce your risk of being bitten or stung by an insect. These are listed below.

Don't panic

  • move away slowly and don't wave your arms around if you encounter wasps, hornets or bees.

Cover exposed skin

  • by wearing long sleeves and trousers if you're outside at a time of day when insects are particularly active, such as sunrise or sunset.

Keep food and drink covered

  • when eating or drinking outside, particularly sweet things. Wasps or bees can also get into open drink bottles or cans you're drinking from.

Avoid using scented products

  • as these can attract insects; such as strong perfumes, soaps, shampoos and deodorants.

Wear shoes outdoors

Apply Insect Repellant

  • to exposed areas of skin, especially in the summer or early autumn, when insect stings are most likely to occur.

Avoid keeping house or car doors and windows wide open

  • or put thin netting or door beads over them to prevent insects getting inside the house.

Avoid areas that attract insects such as:

  • flowering plants, outdoor areas where food is served and areas with rubbish and compost if you can.

In your garden:

  • remove any fallen fruit in your garden regularly and keep a tight-fitting lid on dustbins.

Do not disturb insect nests:

  • wasps build nests in sheltered areas such as trees and roof spaces; if you suspect a nest is in or near your house, arrange to have it removed.

Avoid camping near water

  • such as ponds and lakes as mosquitoes and horseflies are commonly found near water.
Antibiotic Guardianship

Antibiotics should be used responsibly and only when really necessary. Overuse and misuse of antibiotics can lead to antibiotic resistance. This is where the antibiotic becomes less effective at treating certain types of bacterial infection, so they do not work when needed. 

Antibiotics should be taken as prescribed, and it is important to complete the full course, this can reduce the chance of the bacteria developing an immunity to that antibiotic. It is important not to share antibiotics, and always take unused medication to your local pharmacy for disposal.

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