Diagnostic reasoning case · WHO IMCI
Cough and fast breathing in a toddler
Pneumonia is still one of the commonest causes of death in young children, and most of those deaths can be prevented with a correctly counted breathing rate and a few days of amoxicillin. The skill is in the counting and in looking at the chest of a calm child.
- Setting: Urban health centre in a low malaria risk area, with a pulse oximeter
- For nurses, clinical officers, doctors and community health workers trained in IMCI
- Reviewed October 2026
The presentation
Leila, 18 months old, has had a cough for 3 days and a fever since yesterday. Her mother says she is breathing quickly and is not eating much, but she is still breastfeeding. She weighs 11 kg.
| Sign | Value |
|---|---|
| Axillary temperature | 38.4 °C |
| Breathing rate | To be counted |
| Pulse | 136 per minute |
| Conscious level (AVPU) | Alert |
| Weight | 11 kg |
Tests at hand: Pulse oximetry (SpO2) · Malaria rapid diagnostic test (RDT) · Mid-upper arm circumference (MUAC) · HIV rapid test
Starting differential
- PneumoniaStill possible
- Severe pneumonia or very severe disease Must not missStill possible
- Cough or cold (viral upper respiratory infection)Still possible
- Wheezing illness (bronchiolitis, asthma)Still possible
- Croup or an inhaled foreign body (stridor) Must not missStill possible
- MalariaLess likely
- TB or HIV-related lung diseaseLess likely
Work through it
Read each question and decide your own answer first. Then open the model answer and see how the differential changes.
- Step 1 of 7 · Look
What do you check first, and how do you count her breathing so that the number can be trusted?
Model answer
Check the general danger signs: not able to drink or breastfeed, vomits everything, convulsions, lethargic or unconscious. Leila breastfeeds in front of you, has not vomited or had a fit, and is alert. No danger sign.
Count breaths for a full minute while she is calm, on her mother's lap, watching the chest or abdomen move. A crying or feeding child breathes faster: wait until she settles, and count again if the number is borderline.
Age Fast breathing is 2 months up to 12 months 50 or more per minute 12 months up to 5 years 40 or more per minute Leila breathes at 46 per minute, counted twice. At 18 months, that is fast breathing.
Differential now- PneumoniaLeading (moved up)
- Severe pneumonia or very severe disease Must not missStill possible
- Wheezing illness (bronchiolitis, asthma)Still possible
- Croup or an inhaled foreign body (stridor) Must not missStill possible
- Cough or cold (viral upper respiratory infection)Less likely (moved down)
- MalariaLess likely
- TB or HIV-related lung diseaseLess likely
- Step 2 of 7 · Look
Now look at the chest and listen. Which three signs do you look for, and what does each one mean?
Model answer
- Chest indrawing: the lower chest wall goes in when she breathes in. Look when she is calm: it must be clearly visible as she breathes in, not only when she cries or feeds. With fast breathing or alone, it classifies as pneumonia (or as severe if there is also a danger sign).
- Stridor in a calm child: a harsh noise on breathing in. It means the upper airway is narrowed (croup, a foreign body, diphtheria) and is a reason for urgent referral.
- Wheeze: a soft musical noise on breathing out. If there is wheeze with fast breathing or chest indrawing, IMCI gives a trial of a rapid-acting inhaled bronchodilator, up to three times 15 to 20 minutes apart, then counts and looks again before classifying.
No chest indrawing, no stridor, no wheeze. She has a runny nose.
Differential now- PneumoniaLeading
- Severe pneumonia or very severe disease Must not missLess likely (moved down)
- Cough or cold (viral upper respiratory infection)Less likely
- MalariaLess likely
- TB or HIV-related lung diseaseLess likely
- Wheezing illness (bronchiolitis, asthma)Set aside for now (moved down)
- Croup or an inhaled foreign body (stridor) Must not missSet aside for now (moved down)
- Step 3 of 7 · Ask
What else do you ask? Which answers would change the plan?
Model answer
- How long has she had the cough? More than 14 days, or wheeze that keeps coming back, means assessment for TB or asthma.
- Did it start suddenly with choking? (inhaled foreign body)
- Anyone at home with a long cough or on TB treatment?
- The mother's HIV status: chest indrawing in a child who is HIV-exposed or HIV-infected means first dose and referral.
- The other main symptoms: diarrhoea, ear problem; travel to a malaria area.
- Immunisations: pneumococcal, Hib, measles, pertussis.
Cough for 3 days only; no choking. No one at home is coughing. Her mother tested HIV negative in pregnancy and again at 6 months. No diarrhoea or ear problem, no travel. Immunisations up to date.
Differential now- PneumoniaLeading
- Severe pneumonia or very severe disease Must not missLess likely
- Cough or cold (viral upper respiratory infection)Less likely
- MalariaLess likely
- Wheezing illness (bronchiolitis, asthma)Set aside for now
- Croup or an inhaled foreign body (stridor) Must not missSet aside for now
- TB or HIV-related lung diseaseSet aside for now (moved down)
- Step 4 of 7 · Test
You have a pulse oximeter, a malaria RDT, MUAC tape and HIV rapid tests. Which do you use?
Model answer
- Pulse oximetry: yes. IMCI refers a child with oxygen saturation below 90%. Measure on a toe or finger with a good trace while she is calm.
- Malaria RDT: not needed today. In a low malaria risk area, IMCI tests a child with fever only if there is no obvious cause; here pneumonia explains the fever and she has not travelled.
- MUAC: yes, as part of checking every sick child for malnutrition. Severe malnutrition with pneumonia changes the plan.
- HIV test: not needed: her mother has two recent negative results. Offer it if the mother's status is unknown.
Results: SpO2 95% on air. MUAC 142 mm, no oedema.
Differential now- PneumoniaLeading
- Cough or cold (viral upper respiratory infection)Less likely
- Severe pneumonia or very severe disease Must not missSet aside for now (moved down)
- Wheezing illness (bronchiolitis, asthma)Set aside for now
- Croup or an inhaled foreign body (stridor) Must not missSet aside for now
- MalariaSet aside for now (moved down)
- TB or HIV-related lung diseaseSet aside for now
- Step 5 of 7 · Do
Classify Leila. What would make this severe pneumonia instead?
Model answer
Signs Classify as Any general danger sign, stridor in a calm child, or SpO2 below 90% Severe pneumonia or very severe disease Fast breathing and/or chest indrawing Pneumonia: this is Leila No fast breathing, no chest indrawing Cough or cold She has fast breathing with no danger sign, no stridor and a normal oxygen level. This is pneumonia, which IMCI treats at home with oral amoxicillin.
Differential now- PneumoniaLeading
- Severe pneumonia or very severe disease Must not missSet aside for now
- Cough or cold (viral upper respiratory infection)Set aside for now (moved down)
- Wheezing illness (bronchiolitis, asthma)Set aside for now
- Croup or an inhaled foreign body (stridor) Must not missSet aside for now
- MalariaSet aside for now
- TB or HIV-related lung diseaseSet aside for now
- Step 6 of 7 · Do
What do you give, and how?
Model answer
- Oral amoxicillin, at least 40 mg/kg per dose twice a day. At 12 months up to 3 years (10 to under 14 kg): 2 dispersible 250 mg tablets twice a day for 5 days.
- Give the first dose in the clinic. Show her mother how to disperse the tablets in a little breast milk or clean water, and ask her to repeat the instructions back.
- Soothe the throat and relieve the cough with a safe remedy, such as breast milk. Avoid remedies containing codeine, atropine or alcohol.
- Paracetamol only if the fever is 38.5 °C or above.
- Keep breastfeeding often, and offer food again as soon as she will eat.
- Step 7 of 7 · Ask
When must she come back, and what do you do at the review?
Model answer
- Come back at once if she cannot drink or breastfeed, becomes sicker, develops difficult breathing or breathes faster.
- Come back in 3 days for review.
- At the review: any danger sign or chest indrawing now, or breathing no better: refer (she may need second-line treatment). Breathing slower, less fever, eating better: finish the 5 days.
Her chest is infected. This medicine will treat it: two tablets in the morning and two in the evening for five days, even when she seems better. Bring her back straight away if she cannot drink, gets sicker or her breathing becomes harder. Come back in three days so I can check her chest.
Must-not-miss conditions
| Condition | Clues | What to do at first-level care |
|---|---|---|
| Severe pneumonia or very severe disease | Any general danger sign, stridor in a calm child, SpO2 below 90%, severe malnutrition; chest indrawing in a child who is HIV-exposed or infected. | First dose of an appropriate antibiotic, oxygen if available, keep warm; refer urgently. |
| Upper airway obstruction (croup, foreign body) | Stridor in a calm child; sudden onset with choking. | Keep the child calm on the carer's lap, nothing in the mouth; refer urgently. |
| Severe wheeze | Wheeze with fast breathing or indrawing that does not settle after up to three doses of inhaled bronchodilator; difficulty speaking or feeding. | Classify and treat after the bronchodilator trial; refer if danger signs or no response. |
| TB or HIV-related lung disease | Cough for more than 14 days, poor weight gain, a TB contact at home, an HIV-positive or untested mother. | Refer for TB assessment; offer HIV testing. |
Decision at first-level care
Leila has pneumonia: fast breathing (46 per minute at 18 months) without chest indrawing, stridor, danger signs or low oxygen. She is treated at home with oral amoxicillin for 5 days, the first dose given in the clinic, and reviewed in 3 days.
Source: WHO IMCI chart booklet (2014); WHO guideline on management of pneumonia and diarrhoea in children up to 10 years of age (2024).
Treat hereThis patient
- Fast breathing or chest indrawing with no danger sign, no stridor, SpO2 90% or more: oral amoxicillin at home.
- Cough or cold without fast breathing: soothing remedy, no antibiotic, review in 5 days if not improving.
Observe and review
- Wheeze with fast breathing or indrawing: up to three doses of inhaled bronchodilator 15 to 20 minutes apart, then count and look again before deciding.
- Borderline count in an upset child: settle her and count again for a full minute.
Refer
- Any general danger sign, stridor in a calm child, or SpO2 below 90%.
- Severe malnutrition with pneumonia.
- Chest indrawing in a child who is HIV-exposed or infected.
- Not better or worse at the 3-day review.
- Cough for more than 14 days or recurrent wheeze (TB or asthma).
Key learning points
- Count breaths for a full minute in a calm child: 50 or more under 12 months, 40 or more from 12 months to 5 years is fast.
- Look for chest indrawing in a calm child: the lower chest wall moves in as she breathes in.
- Stridor in a calm child, a danger sign or SpO2 below 90% means urgent referral.
- Try a rapid-acting bronchodilator before classifying a wheezing child.
- Pneumonia without danger signs is treated at home with oral amoxicillin and reviewed in 3 days.
Sources
- World Health Organization. Integrated Management of Childhood Illness (IMCI) chart booklet. 2014. Fast-breathing thresholds; chest indrawing, stridor and wheeze; bronchodilator trial; oxygen saturation below 90%; classification; amoxicillin dosing; safe remedy for cough; when to return; 3-day follow-up; malaria testing in low-risk areas.
- World Health Organization. Guideline on management of pneumonia and diarrhoea in children up to 10 years of age. 2024. Oral amoxicillin for pneumonia with fast breathing or chest indrawing.
- World Health Organization. Pocket book of hospital care for children: guidelines for the management of common childhood illnesses, second edition. 2013. Stridor and inhaled foreign body (sudden choking) as causes of cough or difficult breathing; lower chest wall indrawing; avoiding harmful cough remedies; emergency signs.
Adapted from WHO guidance; not endorsed by WHO. This page paraphrases and adapts the WHO publications listed under Sources, which are licensed CC BY-NC-SA 3.0 IGO; the adapted text is shared under the same licence for non-commercial education. Reasoning GP is not affiliated with WHO or any other organisation named here. Use it alongside your national guidelines, essential medicines list and formulary, and your clinical judgement. Doses are given only where they come from a WHO source; otherwise follow your national guideline or formulary.