Antibiotics and Common Infections: When They Help and When They Do Not

An independent educational resource prepared by Mark M. Simonian, MD, FAAP

Sources checked: August 12, 2026     |     Medical review completed: August 12, 2026

This page is for general education only and does not replace individualized medical advice. This resource does not establish a doctor-patient relationship. For questions about your own child, contact your child's current healthcare professional.

Magnolia Pediatrics, Valley Children's Healthcare

2497 E. Herndon Avenue, Suite 101, Clovis, CA 93611     |     559-538-3070

Antibiotics are important medicines when a child has a bacterial infection. They do not treat viruses, which cause most colds, coughs, runny noses, influenza, respiratory syncytial virus (RSV), and many sore throats. A child can feel very sick with a virus; the decision is based on the illness and examination, not how much a family wants relief.

Urgent Warning Signs - Check This First

CALL 911 NOW

  • Trouble breathing; swelling of the lips, tongue, mouth, or throat; widespread hives with breathing or throat symptoms; blue or gray lips or face; fainting with ongoing concerning symptoms; or a child who is limp or unresponsive after any medicine.

  • A seizure, inability to awaken the child, or another life-threatening emergency.

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  • A baby younger than 3 months (12 weeks) with a rectal temperature of 100.4 F (38 C) or higher, even if the baby has recently started an antibiotic.

  • Severe dehydration, a severe or rapidly spreading rash with blistering or skin peeling, repeated vomiting with severe abdominal pain, or a child who looks very ill.

CONTACT YOUR CHILD'S HEALTHCARE PROFESSIONAL TODAY

  • Symptoms are worsening, not following the expected plan, or are returning after clear improvement.

  • A new rash, severe diarrhea, significant abdominal pain, repeated vomiting, or another possible medicine reaction that is not an emergency.

  • You are unsure whether a dose was given, your child vomited a dose, the medicine was spilled, or the prescription is difficult to obtain. Ask before making up, doubling, stopping, or sharing doses.

What Antibiotics Do - and Do Not Do

  • Antibiotics kill or slow certain bacteria. They are used for bacterial infections such as strep throat, some ear infections, some pneumonias, urinary tract infections, and some skin infections. The exact diagnosis determines whether an antibiotic is useful.

  • Antibiotics do not kill viruses. They will not shorten an ordinary viral cold, most coughs, most sore throats, or a runny nose, even when mucus becomes thick, yellow, or green.

  • Using an antibiotic when it is not needed exposes a child to side effects and can contribute to antibiotic resistance, making future bacterial infections harder to treat.

Why “Watchful Waiting” Can Be Good Care

  • Some illnesses improve without antibiotics. When appropriate, a clinician may recommend symptom care and a clear plan for what to watch for instead of prescribing immediately. This is an active medical plan, not a dismissal of the child's symptoms.

  • The clinician may need an examination, a throat test, urine testing, an ear examination, or other information before deciding whether an antibiotic is indicated.

  • Ask when to expect improvement, what symptoms should prompt a call, and how to obtain follow-up. Do not use a leftover antibiotic while waiting.

If an Antibiotic Is Prescribed

  • Give the medicine exactly as prescribed. Use the measuring syringe, cup, or device supplied or recommended by the pharmacist; kitchen spoons are not accurate.

  • Give every dose for the prescribed duration unless the prescriber tells you to change the plan. Do not save doses for later illnesses and do not share antibiotics with another person.

  • Check the label for storage, shaking, food instructions, expiration, and missed-dose advice. The pharmacist is an excellent resource for practical medication questions.

  • Tell all healthcare professionals about a prior suspected medicine reaction. Do not label a child “allergic” without discussing what happened, because the specific symptoms and timing matter.

Common Side Effects and Possible Allergy

  • Common effects can include loose stools, nausea, vomiting, abdominal discomfort, or a mild rash. Contact the child's healthcare professional when a reaction is concerning or persistent.

  • An allergy can involve hives, swelling, wheezing, trouble breathing, or other symptoms soon after a dose. Severe symptoms need emergency care.

  • Diarrhea can occur during or after antibiotics. Offer fluids as directed and seek care promptly for dehydration, blood in stool, severe abdominal pain, high fever, or a child who looks ill.

Comfort Care Still Matters

  • Antibiotics do not directly treat fever, pain, cough, congestion, or poor sleep. Ask about safe symptom relief for the child's age, weight, medical conditions, and medicines.

  • Fluids, rest, nasal saline and suction for young children, a cool-mist humidifier, and honey for cough only for children older than 1 year may be helpful in appropriate circumstances.

  • Do not give prescription medicine, over-the-counter cold medicine, or a home remedy without checking that it is suitable for the child.

Questions Families Can Ask

  • What infection do you think my child has, and how was that diagnosis made?

  • Is an antibiotic needed today, or is observation appropriate?

  • What improvement should we expect, and when should we call again?

  • What are the common side effects, signs of allergy, and instructions if a dose is missed or vomited?

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Sources and Medical Review

Sources checked August 12, 2026. Medical review completed August 12, 2026.