The pressure to prescribe antibiotics for children — from parents who want to do something concrete for a sick child, and sometimes from clinicians who find a prescription quicker than a conversation — is one of the main forces driving antimicrobial resistance worldwide. The CDC describes antibiotic resistance as one of the top public health threats of our time, and roughly 30% of antibiotic prescriptions in outpatient paediatric care are estimated to be unnecessary. Knowing which childhood illnesses are bacterial (and so might respond to antibiotics) and which are viral (and so will not) changes how you respond to your sick child and how you talk to your GP.
This isn't an argument against antibiotics. They are life-saving medicines, and children sometimes genuinely need them. It is an argument for using them when they help and skipping them when they won't.
Healthbooq gives parents evidence-based guidance on managing common childhood illnesses, including when to seek a clinical assessment and what to expect from treatment.
Viral versus Bacterial Infection
The first question with any infection is whether it's viral or bacterial. Viruses — rhinovirus (the main cause of colds), influenza, RSV, rotavirus, adenovirus, parainfluenza and dozens more — cannot be killed by antibiotics. Give your child amoxicillin for a cold and the medicine will have no effect on the virus making them ill. What it will do is expose them to the typical antibiotic side effects (loose stools, rash, occasional thrush, disruption of the gut microbiome) and add a small contribution to the rising tide of resistance.
Bacterial infections — most urinary tract infections, some ear infections, Group A streptococcal tonsillitis, bacterial pneumonia, whooping cough, cellulitis, impetigo — do respond to the right antibiotic, and in those cases the drug genuinely matters.
The difficulty is that symptoms alone often don't tell you which one you're dealing with. A child with a sore throat, fever and trouble swallowing might have a viral upper respiratory infection or might have strep throat. Ear pain and fever after a cold could be viral otitis media (very common, doesn't respond to antibiotics) or bacterial otitis media (does). GPs use the examination, the trajectory of the illness, and sometimes a rapid swab or urine dip to work it out.
Common Childhood Illnesses That Do Not Require Antibiotics
Colds and upper respiratory infections. Almost always viral. Self-limiting in 7–10 days. Manage with fluids, weight-based paracetamol or ibuprofen for fever and discomfort, and saline nose drops if congestion is interfering with feeding. Green nasal discharge — which often appears in the second week as the immune response ramps up — is not a sign of a bacterial infection. It does not mean antibiotics are needed.
Most coughs. Coughing is a symptom, not a diagnosis. Most coughs follow a viral respiratory infection, last up to three weeks, and don't benefit from antibiotics. A cough lasting beyond three weeks, or one with high fever and fast breathing (over 50 breaths per minute in a 1–5 year old), needs a doctor's assessment to rule out pneumonia.
Most sore throats. Around 80–90% of sore throats in children are viral. Even confirmed Group A strep throat resolves in a similar timeframe without antibiotics in most well children — the main reason we treat it is to reduce the small risk of rheumatic fever, which is rare in the UK and other high-income settings.
Most ear infections. Roughly 80% of childhood ear infections clear within a few days without antibiotics. NICE recommends watchful waiting for most children over 6 months — paracetamol or ibuprofen for pain, review at 3 days. Antibiotics are reserved for children who are systemically unwell, those under 2 with infection in both ears, or those not improving after 3 days.
Diarrhoea and vomiting. Mostly viral (rotavirus, norovirus). The treatment is oral rehydration solution in small, frequent sips — not antibiotics, which can actually prolong some bacterial gut infections.
When Antibiotics Are Genuinely Needed
Antibiotics matter — and matter a lot — for: urinary tract infections (any febrile child with no clear focus needs a urine sample); confirmed bacterial tonsillitis (positive rapid strep test, or the classic picture of fever, pus on the tonsils, swollen front-of-neck glands and no cough); bacterial pneumonia; whooping cough (pertussis); skin infections such as cellulitis and impetigo; meningitis or sepsis; and any child who is sick enough to need hospital assessment.
For most of these the AAP and NICE first-line is amoxicillin — for example, amoxicillin 80–90 mg/kg/day divided into two doses for 5–10 days for acute otitis media when antibiotics are needed. Penicillin V is first-line for confirmed strep throat. The specific drug, dose and duration are decided by the prescribing clinician — but if you're given a prescription, finish the course unless told otherwise.
Key Takeaways
Most common childhood illnesses — colds, the majority of ear infections, coughs, sore throats, and most diarrhoea and vomiting — are caused by viruses, and antibiotics do nothing to viruses. Prescribing them for a viral illness will not speed your child's recovery, will not prevent a bacterial complication in most cases, and will disrupt your child's gut bacteria while adding to antimicrobial resistance worldwide. Knowing when antibiotics genuinely help — and being able to accept that a poorly child often does not need them — is one of the most useful things a parent can understand about childhood illness.
