My child has been coughing for 2 weeks after a cold — should I investigate?

Not urgently. It is normal for a cough to persist 2 to 3 weeks after a viral infection in children. If the cough is dry and gradually improving with no fever, wheezing, or weight loss, you can monitor at home. If it exceeds 4 weeks or worsens with new symptoms, schedule a pediatric appointment.

How can I tell if the cough is from asthma or allergies?

Asthma: dry cough with wheezing, shortness of breath, and worsening at night, with laughing, or during exercise. Allergic rhinitis: cough with runny nose, sneezing, nasal itching, and worsening with dust or weather changes. Reflux: cough after eating or lying down after meals. Note the timing and context of the cough — this is the main diagnostic clue for the pediatrician.

Do cough syrups work for children?

Most over-the-counter cough syrups have no proven efficacy in children and are not recommended by the Brazilian Society of Pediatrics for children under 4 years. Pure honey is a safe and effective option for children over 1 year. The key is to treat the underlying cause (asthma, allergy, sinusitis), not just the symptom.

When should I go to the ER because of my child's cough?

Go immediately if there is difficulty breathing, intense wheezing that does not improve, coughing up blood, high fever (above 39 C / 102 F) with lethargy, blue lips or nails, or frequent choking while eating. For chronic cough without these signs, schedule a consultation within the next few days.

My child only coughs at night — could it be asthma?

Yes, recurrent nighttime cough is a classic asthma symptom in children and is frequently mistaken for allergies or a lingering cold. The lying position can also worsen post-nasal drip from allergic rhinitis. If nighttime coughing persists for more than 3 weeks, consult your pediatrician.

Is an antibiotic necessary for chronic cough?

An antibiotic is only indicated when a bacterial infection is confirmed, such as sinusitis with yellow-green discharge and fever, or confirmed pneumonia. Most chronic coughs in children are viral, allergic, or irritative — antibiotics do not work in these cases and their unnecessary use contributes to bacterial resistance.

Chronic Cough in Children: Causes, Diagnosis, and When to See a Pediatrician

Coughing is one of the most common reasons for pediatric consultations — and when it persists for weeks without improvement, parents understandably become worried. The good news: in most cases, chronic cough in children has an identifiable cause and effective treatment. In this guide, I explain how to differentiate cough types, when to investigate, and when to simply monitor at home. If you are an expat family in São Paulo, this information will help you navigate the Brazilian healthcare system with confidence.

What Is Chronic Cough?

Coughing is a natural defense reflex — it helps clear the airways of mucus, dust, viruses, and irritants. In healthy children, coughing up to 10 times per day is considered normal. The concern arises when coughing persists for weeks without improvement.

Classification by duration is essential for the pediatrician to decide when to investigate:

Type	Duration	Approach
Acute cough	Up to 3 weeks	Usually viral, monitor at home
Subacute cough	3 to 4 weeks	Monitor progression, consult if worsening
Chronic cough	More than 4 weeks	Requires medical evaluation

Key Facts About Chronic Cough in Children

5-10%

of children have chronic cough

6 to 8

respiratory infections per year in children

90%

of post-viral cough resolves within 25 days

The 5 Most Common Causes of Chronic Cough in Children

Chronic cough is not a disease in itself — it is a symptom of another condition. Identifying the underlying cause is essential for proper treatment. These are the most frequent causes in pediatric practice:

1. Asthma

Asthma is the most common causeof chronic cough in school-age children. Many asthmatic children do not present the classic wheeze — a recurrent dry cough can be the only manifestation (called “cough-variant asthma”).

Clues: Dry cough, worsens at night and early morning, worsens with exercise or laughing, improves with bronchodilator. Family history of asthma or allergies. Frequently associated with atopic dermatitis.

2. Allergic Rhinitis (post-nasal drip)

Allergic rhinitis causes the nasal lining to produce excess mucus. This mucus drips down the back of the throat (post-nasal drip), irritating it and triggering cough — especially when lying down.

Clues:Cough with runny nose, frequent sneezing, itchy nose and eyes. Worsens with dust, weather changes, or contact with animals. Very common during autumn in São Paulo.

3. Sinusitis

Sinusitis (infection or inflammation of the sinuses) is common in children and often presents as a persistent productive cough, especially upon waking. It frequently develops after a cold that “doesn't get better.”

Clues: Productive cough (with thick yellow-green mucus), worsens upon waking, persistent nasal congestion, sometimes headache or facial pain. A cold lasting more than 10 days without improvement.

4. Gastroesophageal Reflux (GERD)

Stomach acid rises through the esophagus and can reach the throat and even the airways, triggering cough. This is a frequently overlooked cause, especially when the cough has no other respiratory characteristics.

Clues: Cough worsens after meals or when lying down, heartburn, abdominal pain, nausea, nighttime choking. In babies: frequent spitting up, fussiness while feeding, food refusal.

5. Post-Infectious Cough

After a cold or flu, coughing can persist for weeks even after the infection has resolved. This happens because the airways remain hyperreactive — “irritated” — and any small stimulus (cold air, dust) triggers coughing.

Clues: Child had a recent cold or flu, cough gradually improving, no fever, no wheezing, no purulent mucus. Usually resolves on its own within 4 to 8 weeks.

Practical Guide: Cough Type vs. Likely Cause

Use this table as a reference to note your child's cough patterns before the appointment. This information greatly helps the pediatrician:

Cough Type	When It Worsens	Likely Cause
Dry, repetitive	Night, exercise, laughing	Asthma
Dry + sneezing/runny nose	Dust, cold, lying down	Allergic rhinitis
With thick mucus	Upon waking, morning	Sinusitis
Dry or with gagging	After meals, lying down	Reflux (GERD)
Dry, gradually improving	Cold air, dust	Post-infectious

Pediatrician's Tip

Before your appointment, note down: when the cough started, what time of day it worsens (morning, night, after eating), whether it is dry or productive, and what makes it better or worse. This information is worth more than any initial test — it is the key to diagnosis.

Worried about your child's persistent cough?

Dr. Paula can help identify the cause and recommend the right treatment. Schedule a consultation in Itaim Bibi, Sao Paulo.

Talk to the Pediatrician

Red Flags: When to See the Pediatrician Immediately

Most chronic coughs in children are benign and can wait for a scheduled appointment. But certain signs indicate the need for urgent evaluation:

Go to the Emergency Room if the Cough Is Accompanied by:

Difficulty breathing — rapid breathing, visible rib retractions
Intense wheezing that does not improve with bronchodilator
Coughing up blood or dark-colored sputum

High fever (above 39 C / 102 F) with lethargy
Blue or purple lips/nails (cyanosis)
Frequent choking while eating or drinking

Schedule a Pediatric Appointment Within the Next Few Days If:

Cough persists for more than 4 weeks
Cough disrupts sleep or daily activities
Child has weight loss or reduced appetite
A cold that has not improved after 10 days
Recurrent cough in episodes (comes and goes)

How the Pediatrician Investigates Chronic Cough

The investigation starts with a detailed history — a conversation about when the cough began, what it sounds like, what worsens or improves it — followed by a physical examination. In most cases, the clinical history already points the way. Complementary tests may include:

Chest X-ray

Initial exam when there is suspicion of pneumonia, foreign body, or lung abnormalities. Simple, quick, and painless.

Spirometry

For children over 6 years. Measures lung volume and airflow speed. If obstruction improves with a bronchodilator, it suggests asthma.

Allergy Testing

Skin prick test or specific IgE blood test to identify allergic triggers. Important when allergic rhinitis or allergic asthma is suspected.

Therapeutic Trial

In young children, the pediatrician may start treatment for the most likely cause (e.g., inhaled corticosteroid for 8 weeks). If the cough improves, the diagnostic hypothesis is confirmed.

Myths and Facts About Cough in Children

Myth: “Cough syrup will fix it”

Most over-the-counter cough suppressants have no proven efficacy in children, and the Brazilian Society of Pediatrics does not recommend them for children under 4. They can mask important symptoms and delay a correct diagnosis. Treatment should target the underlying cause.

Myth: “Persistent cough needs an antibiotic”

Antibiotics are only indicated when there is a confirmed bacterial infection (bacterial sinusitis, pneumonia). Most chronic coughs are viral, allergic, or irritative — antibiotics do not work in these cases and their unnecessary use contributes to bacterial resistance.

Fact: Honey helps relieve cough

Pure honey is recommended as a safe option to relieve cough in children over 1 year of age. A teaspoon before bed can help. Never give honey to babies under 12 months (risk of botulism).

Fact: Hydration and humidity help

Keeping the child well hydrated helps thin the mucus. Using saline nasal drops and maintaining moderate humidity in the home are simple and effective complementary measures.

Treatment: Treat the Cause, Not the Symptom

The fundamental principle is: identify the causeand direct treatment accordingly. There is no generic treatment for “chronic cough” — each cause has its own approach:

If It Is Asthma

Inhaled corticosteroid (daily maintenance)
Rescue bronchodilator (for flare-ups)
Environmental control (dust mites, mold)

If It Is Allergic Rhinitis

Nasal corticosteroid spray
Antihistamine if itching is severe
Saline nasal irrigation

If It Is Sinusitis

Antibiotic (if bacterial infection confirmed)
Frequent nasal irrigation
Nasal corticosteroid to reduce inflammation

If It Is Reflux

Elevate the head of the bed
Avoid eating 2 hours before bedtime
Antacid medication if prescribed

Cough by Age Group: What to Consider

Babies (0 to 12 months)

Persistent cough in young babies requires special attention — learn when to take your baby to the pediatrician. Consider bronchiolitis, reflux, whooping cough (especially if the vaccination schedule is incomplete), and rarely, congenital malformations. Babies under 3 months with persistent cough should be evaluated urgently.

1 to 5 years (preschoolers)

This is the age with the highest incidence of respiratory infections (especially in children attending daycare). Post-infectious cough and allergic rhinitis are the most common causes. Special attention should be given to the possibility of an aspirated foreign body (sudden cough after choking in an otherwise healthy child).

6 to 12 years (school-age)

Asthma is the most common cause in this age group. Spirometry can be performed to confirm the diagnosis. Persistent allergic rhinitis and sinusitis are also frequent. In rare cases, psychogenic cough (habitual) may emerge — it disappears during sleep.

How to Prevent Chronic Cough

Keep vaccinations up to date — protects against whooping cough, flu, and other respiratory infections
Environmental control — avoid dust, mold, cigarette smoke, and strong-smelling products
Regular nasal irrigation with saline, especially during autumn and winter
Treat rhinitis and asthma preventively — do not wait for a flare to start medication
Adequate hydration — water and fluids help keep mucus thin
Frequent handwashing — the primary prevention against viral infections

Pediatrician's Tip for Expat Families

In São Paulo, the transition to autumn (March-April) brings dropping humidity and increased pollution — factors that worsen rhinitis, asthma, and chronic cough. If your child already has a history of respiratory allergies, speak with your pediatrician about starting prevention before the cold months. International health insurance typically covers these consultations — Dr. Paula provides English-language invoices for reimbursement.