Home
School and family
Family Health
Common childhood illnesses: When should kids stay off school?

Common childhood illnesses: When should kids stay off school?

When you've got a child at school it can feel like they're constantly ill or suffering from some childhood ailment. Do they need to stay off school every time though or can you treat it while they continue their studies? Our resident GP explains 11 of the most common childhood illnesses and the school absence rules that apply to each one.

young boy in a classroom blowing his nose

Dr Philippa Kaye

Published: November 4, 2025 at 4:23 PM

Save

From the moment children go back to school in September to when they break up in July, they bring home a constant supply of colds, ailments and childhood illnesses. It's no surprise – putting a group of children in a warm classroom in close proximity means bugs will spread quickly, but it still makes life very tricky for parents who need to work and aren't sure whether their child is too sick to go into school.

In fact, it's estimated that school-age children will have on average around five to six illnesses each year, ranging from common colds to sick bugs. Alarmingly this number goes up to an average of 12 illnesses per year for younger pre-school children in daycare settings.

Do you really need to keep your child home every time they catch the latest illness doing the classroom rounds though? And if so, are there specific rules on how long they have to be at home before they're allowed back? We spoke to NHS GP Dr Philippa Kaye to answer all your questions about common childhood ailments and the school exclusion policies that come with them, to help you make a sensible decision on when and when not to send your child to school.

11 common childhood illnesses and school attendance rules

1. Head lice (nits)

girl scratching head with nits in classroom

What it is: Nits are actually the eggs of head lice, which are tiny insects that live on the scalp and hair. Each louse can lay multiple eggs which hatch about a week after being laid.

Symptoms:

Itching, especially at the back of the neck and behind the ears.
On checking the head you may find live lice or eggs.
Not everyone will have an itchy scalp with head lice, so if you get an email from school informing you that someone in the class has nits please check your child’s scalp.

Treatment:

Use wet-combing, apply lots and lots of conditioner, separate the hair and use a fine-toothed detection comb over several days (e.g., days 1,5,9,13) to catch newly hatched lice.
If wet-combing is not effective, you can buy medicated lotions or sprays over the counter. Some advise repeating the treatment after a week.

Exclusion rules:

There is no need to keep children off school because of head lice. However it is sensible to inform the school so that they can inform parents in the class so that they also check their children’s heads. This should be done anonymously, e.g. ‘there has been a case of head lice in the class’, rather than identifying the child.

2. The common cold

What it is: We’ve all had one – the cold is a viral infection of the upper respiratory tract, nose, and throat.

Symptoms:

Runny or blocked nose
Sneezing
Sore throat
Mild cough
Fever (not always present)
Fatigue

Treatment:

Try and prevent colds spreading by coughing/sneezing into a tissue and washing your hands afterwards.
Make sure they are drinking plenty of fluids, get rest if they need it and, if they have aches and pains or are unwell with a fever, paracetamol or ibuprofen can be used. Remember treat the child and not the number on the thermometer.
Use tissues, hand hygiene, and covering coughs/sneezes

Exclusion rules:

If the child is well enough and doesn’t have a high temperature, they can attend school with a cold – children will get multiple colds in a year.
If they have a high fever or are significantly unwell, they should stay home until the temperature goes down.

3. Stomach bugs

school child with blanket wrapped round them and a hot water bottle

What it is: A tummy bug is generally a viral infection of the gastrointestinal tract, most commonly viral but it can be bacterial.

Symptoms:

Nausea, vomiting
Diarrhoea
Stomach cramps
Fever
Fatigue

Treatment:

Make sure they are drinking fluids to avoid dehydration
Giving fluids little and often can help them keep them down.

Exclusion rules:

Children must stay away from school or childcare until 48 hours after the last episode of vomiting or diarrhoea, and until they are well enough to return.

4. Threadworms

What it is: Called threadworms because the worms look like tiny pieces of thread, these tiny worms (pinworms) infect the intestines and lay eggs around the anus, especially at night. They are very common in children.

Symptoms:

Itchy bottom, especially at night
Irritability, difficulty sleeping – due to the itching

Treatment:

You can buy over-the-counter treatment generally containing mebendazole from a pharmacy. The whole family will need to be treated and treatment is often repeated after two weeks.
At the same time it is important to follow the hygiene rules around washing bedding and towels, wearing underwear at night, handwashing and more.

Exclusion rules:

No exclusion needed — children can attend school while being treated.

Threadworms in babies and children: signs, symptoms and treatment

5. Ringworm

What it is: Ringworm is a skin infection caused by a fungus, often creating ring-shaped, sometimes itchy rash which can occur on any part of the body.

Symptoms:

Circular red or silvery rash, often itchy
Scaly, inflamed skin around the ring
If ringworm occurs on the scalp it may lead to patches of hair loss

Treatment:

For ringworm on the face or the body there are over-the-counter antifungal creams available or see your GP if they aren’t working.
For ringworm on the scalp see your GP for treatments.

Exclusion rules:

No need to keep child off school once treatment has begun.

6. Impetigo

What it is: Impetigo is a highly contagious bacterial infection of the skin, caused by a bacteria named Staphylococcus

Symptoms:

Red sores or blisters, often around the nose, mouth, hands
Honey-coloured crust may develop on the lesions, which may ooze fluid
The lesions might be sore or itchy

Treatment:

Antibiotic cream or tablets, depending on severity.
Good hygiene is also important, for example do not share towels.

Exclusion rules:

Child should stay off until sores are crusted and healed, or 48 hours after starting antibiotic treatment.

7. Conjunctivitis

conjunctivitisjpg

What it is: Conjunctivitis is inflammation of the conjunctiva, which is one of the layers of the eye. It has various causes including allergies such as hayfever, but here the discussion is around infective conjunctivitis. This tends to be viral and can be very infectious, but can be bacterial.

Symptoms:

Redness in one or both eyes
Sticky or watery discharge, especially morning crusting
Itchy or gritty feeling in the eye

Treatment:

Most infective conjunctivitis is viral which tends to go away on its own. Keep your eyes clean and over-the-counter soothing and lubricating drops can be used.
If conjunctivitis is bacterial, then antibiotic eye drops or ointment is used. These are available over the counter and from your doctor.

Exclusion rules:

Usually no need to keep off school or nursery unless your child is also unwell, say with a fever.

8. Chickenpox

What it is: Chickenpox is a viral infection caused by the varicella-zoster virus.

Symptoms:

Generally the child may be unwell in the few days before the rash appears, perhaps with a fever, tiredness or aches and pains.
Then over the next few days red itchy spots appear in crops, progressing to fluid-filled blisters then crusting

Treatment:

The mainstay of treatment is to try and relieve the itching with lotions such as calamine lotion or aloe vera gel, oat baths, and/or oral antihistamines.

Exclusion rules:

Keep off school until all the blisters have crusted over, usually about 5 days after rash appears.

Chickenpox in children: signs, symptoms and how to treat it

9. Scarlet fever

What it is: Scarlet fever is due to a bacterial infection (with Group A Streptococcus) which causes a rash, sore throat and fever.

Symptoms:

Initially the child may be unwell with a fever and general tiredness and a sore throat.
A red rash can then develop, which classically feels like sandpaper, commonly on chest/abdomen then spreading
There may initially be a white coating to the tongue which then turns very bumpy and red and is known as “strawberry tongue”

Treatment:

If you are concerned about scarlet fever please see your GP, the treatment is with antibiotics.

Exclusion rules:

Your child will not be allowed to return to school until they have been on antibiotics for 24 hrs.

Scarlet fever in children: signs, symptoms and treatment

10. Hand, Foot and Mouth Disease

hand foot and mouth white skin

What it is: Hand, foot and mouth disease is a common viral illness caused by a group of viruses called enteroviruses.

Symptoms:

Initially there may be a fever, perhaps a sore throat and tiredness
Classically the rash of hand foot and mouth involves small blisters which can be in the mouth, on the hands and feet and sometimes also on the buttocks.

Treatment:

This is a viral infection so antibiotics are not needed.
Instead make sure they are keeping up their fluid intake and give paracetamol/ibuprofen if needed.

Exclusion rules:

If child is well enough, and doesn’t have a fever they can attend school even with symptoms.

Hand, foot and mouth disease: signs and symptoms

11. COVID-19

What it is: Covid-19 is probably one of the most famous viruses, and needs little introduction!

Symptoms:

Symptoms include a fever and a cough, loss or change of smell or taste

Treatment:

Most children will improve with rest, keeping up their fluid intake and paracetamol/ibuprofen if needed.
If you are concerned that your child is more unwell please see your doctor.

Exclusion rules:

If your child tests positive for Covid-19 they should not return to school for 3 days. If they are over 18 then they should stay at home for 5 days, starting from the day the test was taken.

Remember, this is general guidance, if you are concerned about your child, please seek medical advice.

Please note: this advice is not personalised or meant to replace individual advice given to you about your child by your doctor or medical team. As always, if you are concerned about your child’s health then please seek medical advice.

About our expert

Dr Philippa Kaye is a GP, media doctor and author with a particular interest in women's, children's and sexual health. She has written multiple books including The Science of Menopause, Breasts: An Owner's Guide and Doctors Get Cancer Too, her memoir of being 39 years old, a busy doctor and mother when she was diagnosed with bowel cancer.

Authors

Dr Philippa Kaye

Dr Philippa KayeGP