Mosquito bites: treatment, how long they last and when to see a doctor

The NHS says you can often treat an insect bite or sting without seeing a GP. If there is nothing in your skin, wash it with soap and water to help lower the chance of infection. The bite or sting should get better in a few days.

There are some things you can do to ease symptoms. The NHS lists the following, and says to do these and avoid the things listed.

The NHS says the main symptoms of an insect bite or sting are pain where you were bitten and a small swollen lump on the skin. The lump may look red, which may be more difficult to see on black or brown skin, but you should be able to feel it. Mosquito bites are usually small, raised and itchy.

You may have a mild allergic reaction, where the skin becomes itchy and raised around the bite, and you can have lots of bites grouped together in a small area. NICE Clinical Knowledge Summaries explains that mosquitoes puncture the skin with piercing mouthparts, and that bites usually occur as a result of feeding.

The NHS says insect bites and stings are not usually serious and get better in a few days. NICE CKS says most insect bite reactions resolve within hours to several days, but occasionally they may persist for weeks or months, for example if tick mouthparts are retained in the skin or an infestation remains untreated.

Large reactions can happen. For stings, NICE CKS describes large local reactions that extend more than 10 cm from the site and peak 24 to 48 hours after the sting. If symptoms get worse or are not getting any better, the NHS says to ask for an urgent GP appointment or get help from NHS 111.

The remedies the NHS supports are simple: cold, antihistamines and hydrocortisone cream, with paracetamol or ibuprofen for pain. It advises against home remedies such as bicarbonate of soda.

The NHS says do not use antihistamine cream if you had caterpillar hairs on your skin, and that a pharmacist can recommend treatments such as antihistamines and steroid creams. NICE CKS notes that the evidence supporting oral analgesics, antihistamines and corticosteroids for symptom relief is limited.

The NHS says the area may become more swollen and painful if the bite or sting gets infected. It says to see a pharmacist if you or your child aged 1 year or older has an insect bite and the skin around it feels hot or looks red, it is painful, the area looks swollen, or there is pus or fluid coming out. A pharmacist can recommend treatments and give the same antibiotics as a GP if the bite is infected.

NICE CKS says complications can include allergic reactions ranging from angio-oedema to anaphylaxis, systemic toxicity following multiple stings, transmission of infectious diseases such as Lyme disease, and secondary bacterial infection.

The NHS says bites from some insects can cause illnesses, such as Lyme disease from ticks, scabies from mites and malaria from mosquitoes in certain parts of the world. NICE CKS says referral or specialist advice may be required for people with unusual or travel-associated bites or stings.

If you become unwell with a fever or flu-like symptoms after returning from travel abroad, tell the doctor where you have been.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you or your child has been bitten or stung by an insect and your symptoms get worse or are not getting any better, you were stung in your mouth or throat or near your eyes, you have tummy pain and are being sick, you feel dizzy or lightheaded, you have a high temperature and swollen glands, you were stung more than once, or you have had a serious allergic reaction to an insect bite or sting before.

Call 999 if your lips, mouth, throat or tongue suddenly become swollen, you are breathing very fast or struggling to breathe, your throat feels tight or you are struggling to swallow, your skin, tongue or lips turn blue, grey or pale, you suddenly become very confused, drowsy or dizzy, someone faints and cannot be woken, or a child is limp, floppy or not responding normally. You may also have a swollen, raised or itchy rash. These can be signs of a serious allergic reaction.

The NHS says to see a pharmacist for a bite that feels hot, looks red, is painful, swollen or has pus coming out. See a GP if a child under 1 year old has an insect bite or sting, or if you think you or your child have been bitten by a tick and have flu-like symptoms or a round or oval rash that may look like a bullseye.

Most bites are managed with advice from a pharmacist, who can recommend antihistamines and steroid creams and can supply antibiotics for infected bites on the same basis as a GP. A GP or NHS 111 is the route for worsening symptoms, bites in young babies and tick bites.

Private GP services can see a worsening bite quickly, but the advice is the same. Seek urgent care through 999 for signs of a serious allergic reaction rather than waiting for an appointment.