Clinical Guides
Croup
A source-grounded paediatric guide to recognising viral croup, grading upper-airway obstruction, treating without distress and escalating safely in Indian emergency settings, prepared for specialist review.
MedNext Academy | 14 min read
Croup
A source-grounded paediatric guide to recognising viral croup, grading upper-airway obstruction, treating without distress and escalating safely in Indian emergency settings, prepared for specialist review.
Summary
Croup, or acute viral laryngotracheitis, is a clinical syndrome of upper-airway inflammation that typically produces a barking cough, hoarse voice and inspiratory stridor in a young child. Symptoms often follow coryza, worsen at night and fluctuate with crying or agitation. Most episodes are mild, but swelling in a small paediatric airway can progress rapidly. The immediate task is not to identify a particular virus; it is to decide whether stridor occurs only when upset or also at rest, whether air entry and respiratory effort are adequate, and whether fatigue, cyanosis or altered consciousness suggests impending obstruction.
Keep the child calm, preferably upright with a caregiver, and avoid unnecessary separation, painful procedures or forced throat examination. Corticosteroid treatment improves symptoms and reduces return care across severity groups. Moderate or severe obstruction usually requires nebulised adrenaline as a temporary airway intervention while steroid effect develops, followed by monitored observation because adrenaline benefit wanes. Oxygen is indicated for hypoxaemia or severe illness but should be delivered by the least distressing method possible.
Typical croup needs neither routine radiography nor antibiotics. A toxic child, drooling, dysphagia, sudden choking, poor response to appropriate treatment or a course outside the usual pattern should trigger consideration of epiglottitis, bacterial tracheitis, foreign body, deep-neck infection, anaphylaxis or another airway diagnosis. This educational draft cannot replace local resuscitation, paediatric airway or transfer protocols.
How Common Is It?
Croup is a common cause of acute stridor and upper-airway obstruction in childhood. It occurs most often from roughly six months to three years, reflecting both viral exposure and the vulnerability of a narrow subglottic airway, although younger infants and older children can be affected. Recurrent episodes outside the typical age range deserve closer review for structural airway disease, reflux-associated symptoms, allergy or another diagnosis. Parainfluenza viruses are classic causes, but respiratory syncytial virus, influenza, adenovirus, rhinovirus, enteroviruses, metapneumovirus and coronaviruses can produce a similar syndrome. Routine viral identification does not usually alter acute treatment.
Presentations cluster during periods of respiratory-virus circulation and often rise in the evening and overnight. Most children have mild disease and recover without admission; a minority need nebulised adrenaline, observation, oxygen or airway support. Published emergency-department cohorts cannot be used as community incidence because they overrepresent families with access to hospital care and children whose symptoms appeared severe. Admission and intensive-care proportions also vary with referral thresholds, geography and service capability.
For Indian practice, a single national incidence is not asserted here. Population density, household smoke, viral seasonality, travel time, vaccination coverage and the ability of first-contact facilities to recognise stridor all shape burden. Clinically, the useful fact is that croup is frequent but serious mimics are uncommon and dangerous. Familiarity must not produce complacency: every encounter requires a fresh assessment of severity, age, time course, hydration, caregiver capacity and access to urgent reassessment.
Risk Factors
Age is the principal susceptibility factor because small changes in subglottic calibre create disproportionately large resistance to airflow in infants and toddlers. Previous croup increases the likelihood of another episode, and some children have recurrent spasmodic presentations. Very young age, pre-existing airway narrowing, craniofacial or upper-airway anomaly, previous airway surgery or prolonged intubation can reduce physiological reserve. Neuromuscular weakness, significant cardiopulmonary disease, immunocompromise and severe intercurrent infection may complicate assessment or recovery, even though they do not define viral croup.
Exposure risks mirror other respiratory viruses: household or childcare contact, crowding and poor ventilation facilitate spread. Tobacco smoke and biomass exposure can worsen respiratory symptoms and should be addressed without blaming the family. Lack of Hib or diphtheria immunisation does not cause viral croup but makes dangerous alternative diagnoses more credible. Ask specifically about vaccination because epiglottitis and diphtheria require different infection-control, airway and antimicrobial pathways.
Risk is also created by circumstances. A child who lives several hours from paediatric care, has no reliable overnight transport or whose caregiver cannot recognise stridor at rest may need longer observation than an otherwise similar child near a hospital. Agitation itself can worsen dynamic obstruction; repeated examination, venepuncture, supine positioning and masks forced onto the face may turn compensated distress into decompensation. Sedatives are hazardous outside a controlled airway plan. Previous apparent improvement after home steam does not establish safety, and steam exposure carries a burn risk. Severity and trajectory, rather than the loudness of stridor alone, should guide action.
Diagnosis
Croup is diagnosed clinically from the characteristic cough, voice change, stridor and course. Assessment should occur where skilled airway help and resuscitation equipment are available if disease appears severe. Observe before touching the child. A quiet child with diminishing stridor may be improving, but reduced sound with poor air entry, exhaustion or reduced consciousness may instead mean critical obstruction.
History
Ask when coryza, fever, barking cough, hoarseness and noisy breathing began; whether stridor occurs at rest, during sleep or only with crying; and whether symptoms are worsening. Clarify drooling, dysphagia, refusal to drink, muffled voice, choking, allergen exposure, neck pain, cough paroxysms and previous similar episodes. Record age, prematurity, airway history, intubation, comorbidity, immunisation, medicines already given and access to urgent review. Sudden onset while eating or playing suggests a foreign body. High fever with progressive toxicity raises bacterial disease.
Examination
Keep the child with the caregiver and assess appearance, interaction, colour, respiratory rate, heart rate, work of breathing, stridor at rest, air entry, recession and fatigue. Pulse oximetry is useful in significant disease but normal saturation does not exclude dangerous upper-airway narrowing. Look for rash, facial swelling, drooling, neck swelling or asymmetry without provoking distress. Do not force the mouth open or lie down a child with suspected epiglottitis.
Investigations
No laboratory test or radiograph is routinely required in typical croup. Imaging, blood sampling, viral testing or airway endoscopy should be reserved for atypical, severe, recurrent or treatment-resistant presentations and performed only where the airway can be protected. A radiographic sign is neither necessary nor sufficiently reliable to override clinical reasoning.
Differential Diagnosis
Epiglottitis should be considered when a febrile, toxic child has severe sore throat, drooling, dysphagia, tripod positioning, muffled voice or soft stridor with little barking cough. Keep the child calm, avoid throat instrumentation outside a planned controlled airway, summon senior anaesthetic, ENT and paediatric help, and follow the local antimicrobial and infection-control pathway. Hib vaccination has reduced classic disease but has not abolished epiglottitis from all organisms or ages.
Bacterial tracheitis often follows a viral prodrome but progresses to high fever, toxicity, thick secretions and severe obstruction with an incomplete or transient response to nebulised adrenaline. It can require urgent airway clearance, culture and intravenous antimicrobials. Foreign-body aspiration is suggested by abrupt choking, cough or stridor, asymmetrical air entry, absence of a viral prodrome or persistent symptoms; a normal chest radiograph does not exclude it. Retropharyngeal or peritonsillar infection may cause fever, neck stiffness, drooling, trismus, unilateral swelling or muffled voice.
Anaphylaxis is more likely after an exposure with rapid facial or tongue swelling, urticaria, wheeze, shock or gastrointestinal features and requires immediate intramuscular adrenaline through the anaphylaxis pathway, not nebulised adrenaline alone. Diphtheria remains relevant with incomplete immunisation, pharyngeal membrane, cervical swelling or blood-stained discharge and needs isolation and public-health action. Laryngomalacia and other congenital lesions cause chronic or recurrent stridor. Vocal-cord dysfunction, airway haemangioma, trauma, thermal injury and angioedema are additional possibilities. The safest differential is driven by onset, toxicity, swallowing, cough character, immunisation and objective response, never by a single sound label.
Management
First minimise distress. Allow the child to choose a comfortable position with the caregiver, avoid repeated observations that require struggle, and bring senior airway expertise early for severe disease. Give corticosteroid to children assessed in hospital with croup; oral dexamethasone is widely used because one dose is effective and vomiting is uncommon, while an intramuscular or intravenous route may be required if oral medicine cannot be retained or obstruction is severe. Local protocols differ on dose and alternatives, so document drug, route, dose and time rather than assuming equivalence.
For stridor at rest, marked recession or more severe obstruction, give nebulised adrenaline promptly according to the current paediatric emergency protocol. It can improve airway obstruction within minutes, but the effect is temporary and does not replace steroid or observation. Reassess work of breathing, stridor at rest, air entry, colour, mental state and need for repeat treatment. Provide oxygen for hypoxaemia or severe illness using a non-threatening technique. Do not delay transfer while pursuing unnecessary tests.
Escalate early if repeated adrenaline is needed, response is inadequate, the child is tiring or diagnosis is uncertain. An experienced paediatric airway team should plan intubation with difficult-airway and surgical-airway backup; attempts by an unprepared operator can precipitate complete obstruction. Routine humidified mist has not shown meaningful benefit, and steam risks burns. Heliox may be considered only in specialist environments because evidence is limited and it must not delay definitive airway care. Discharge requires sustained clinical stability after the applicable observation period, no stridor at rest, adequate intake, caregiver understanding and feasible return access.
Prescribing Information
Dexamethasone is the best-studied corticosteroid for croup. The Canadian Paediatric Society describes a single oral dose of 0.6 mg/kg, while some institutional protocols use lower doses in milder disease and the Royal Children's Hospital guideline stratifies treatment by severity. The NHM F-IMNCI participant module also lists a single 0.6 mg/kg dose for children brought or referred to hospital. These are cited educational examples, not a prescription for an unassessed child. Formulation concentration, maximum dose, route, vomiting, comorbidity and local protocol must be checked. Prednisolone is used in some pathways, but its duration and comparative evidence differ; do not improvise repeated courses.
Nebulised adrenaline is used for moderate to severe obstruction or deterioration. Racemic adrenaline is not universally stocked; L-adrenaline 1:1000 is commonly used in India. The NHM F-IMNCI module specifies 2 mL of 1:1000 adrenaline with 2 mL normal saline, whereas other protocols use weight-based or different maximum regimens. Follow the local high-alert medicine protocol, verify concentration aloud and monitor response and heart rate. A medication error between 1:1000 and other concentrations can be serious. Clinical benefit usually fades within about two hours, so apparent improvement is not a reason for immediate unobserved discharge.
Antibiotics do not treat uncomplicated viral croup. Salbutamol does not target fixed upper-airway oedema and should not be used as a croup substitute. Cough suppressants, sedating antihistamines and sedatives may obscure fatigue or impair breathing. Antipyretic or analgesic medicine may improve comfort when correctly dosed, but it does not treat obstruction. Every medicine decision in an infant, child with comorbidity or uncertain diagnosis requires the current paediatric formulary and senior clinical judgement.
When to Refer
Arrange emergency transfer or senior paediatric assessment for stridor at rest with significant recession, cyanosis, low oxygen saturation, reduced air entry, fatigue, altered consciousness, recurrent apnoea, poor response to adrenaline or any suspicion of impending obstruction. Repeated nebulised adrenaline, need for supplemental oxygen, dehydration, inability to drink or diagnostic uncertainty generally requires hospital observation or admission. Transfer should be clinician-to-clinician, with the child kept calm, monitoring proportionate to severity and a team capable of managing deterioration during transport. Do not send a critically obstructed child in an unstaffed vehicle.
Refer urgently when features suggest epiglottitis, bacterial tracheitis, foreign body, deep-neck infection, anaphylaxis, diphtheria, airway trauma or a structural lesion. In these situations, ENT, anaesthesia, paediatric intensive care, infectious diseases or public-health services may be needed. The referring clinician should state the time and response to steroid and adrenaline, current respiratory effort, oxygen requirement, immunisation status, suspected alternative and anticipated airway difficulty.
Non-urgent paediatric or ENT review is appropriate for recurrent episodes, presentation below six months or beyond the usual preschool range, persistent stridor between infections, abnormal voice, feeding-related symptoms, poor growth, previous intubation or repeated severe attacks. Discharge from first-contact care is only reasonable after stable improvement for the observation period specified by local protocol, no stridor at rest, comfortable breathing, adequate hydration and a competent caregiver with written return precautions. Distance, night travel, language and telephone access are legitimate disposition factors rather than social footnotes.
Red Flags
Red flags for critical upper-airway obstruction include severe or increasing recession, reduced air entry, exhaustion, reduced respiratory effort after prolonged distress, cyanosis, pallor, agitation progressing to drowsiness, altered consciousness, bradycardia or inability to maintain oxygenation. Stridor may become softer when airflow falls, so a quieter chest in a deteriorating child is ominous. Call resuscitation and senior airway teams immediately, preserve spontaneous breathing, minimise interventions and prepare a controlled airway plan. Oxygen and nebulised adrenaline can be given while help arrives, but neither should create delay or false reassurance.
Red flags for another diagnosis include drooling or inability to swallow, tripod posture, muffled rather than simply hoarse voice, toxic appearance, high or persistent fever, neck swelling or stiffness, sudden choking, unilateral signs, facial oedema, urticaria, shock, a pharyngeal membrane, trauma or burn exposure. Poor or short-lived response to appropriate croup therapy also requires diagnostic reset. Do not repeatedly label treatment-resistant obstruction as severe viral croup while missing pus, a foreign body or allergic swelling.
At home after discharge, caregivers should seek urgent care for stridor while the child is calm, worsening recession, blue or grey colour, pauses in breathing, unusual sleepiness, inability to drink, drooling or rapidly worsening symptoms. They should call emergency services rather than drive if the child is severely breathless, cyanosed or difficult to wake. Steam inhalation is not a rescue treatment and can cause burns. The discharge explanation should use teach-back and specify the nearest capable facility, not merely say to return if worried.
Indian Clinical Context
The NHM 2023 F-IMNCI participant module provides an Indian facility pathway that distinguishes mild croup from moderate to severe disease using stridor at calm, emergency signs, rapid breathing, chest indrawing and oxygenation. It recommends home-care advice and steroid for mild presentations reaching hospital, and admission, steroid, nebulised adrenaline, oxygen and airway escalation for more severe disease. This national training resource is highly relevant, but institutional paediatric emergency and drug-concentration protocols remain necessary because staff skill, equipment and referral capability vary.
At peripheral facilities, the priorities are recognition, calm handling, correctly prepared first-line treatment, early communication with the receiving centre and safe transport. A pulse oximeter reading should be checked for probe fit and signal and interpreted with appearance and work of breathing. Lack of an intensive-care bed should accelerate coordination, not encourage repeated unmonitored adrenaline. Oxygen delivery should avoid struggling when possible. Document vaccine history because incomplete Hib or diphtheria protection changes the differential and may require isolation and public-health notification.
Families may first try steam, herbal preparations, leftover antibiotics or cough mixtures. Explain respectfully that humidified steam has not demonstrated reliable benefit, antibiotics do not treat uncomplicated viral croup and sedating remedies can be unsafe. Provide advice in the caregiver's preferred language, including what stridor at rest sounds like, how to keep the child comfortable, fluid guidance and exact red flags. Medicine availability differs across government and private settings, especially dexamethasone formulations and nebuliser equipment. The guide therefore presents evidence and decision principles rather than claiming that one international pathway can be copied unchanged into every Indian facility.
NMC Competency Mapping
Croup integrates paediatric respiratory assessment, emergency recognition, pharmacology, infection control and communication within the NMC Competency Based Medical Education Curriculum 2024. The learner should explain why subglottic oedema produces inspiratory stridor, distinguish upper-airway noise from wheeze and relate airway radius to rapidly increasing resistance in a small child. They should elicit onset, cough character, stridor at rest, swallowing difficulty, choking, vaccination and prior airway history, then assess appearance, air entry, recession, oxygenation, hydration and mental state without provoking avoidable distress.
Applied clinical reasoning requires separating typical viral croup from epiglottitis, bacterial tracheitis, foreign body, anaphylaxis, diphtheria and deep-neck infection. The learner should know that routine radiography and antibiotics are inappropriate in typical disease, that corticosteroid is the treatment foundation, and that nebulised adrenaline has rapid but temporary benefit in moderate or severe obstruction. They should be able to state the need for monitored observation and early airway escalation, while checking a current paediatric formulary rather than recalling an unverified concentration.
A supervised simulation can assess calm team behaviour, ABC evaluation, caregiver positioning, correct escalation language, high-alert medicine verification and structured transfer handover. Communication competence includes teach-back of discharge red flags and consideration of distance and access. Curriculum mapping does not authorise an undergraduate to force a throat examination, sedate a distressed child, prescribe independently, intubate without competence or delay senior help. Patient safety is demonstrated by recognising limits, controlling agitation and escalating before fatigue.
Key Exam Pearls for NEET PG
The classic triad is barking cough, hoarse voice and inspiratory stridor after a viral prodrome, most often in a child between six months and three years. Stridor only when agitated suggests milder disease; stridor at rest, recession and impaired air entry indicate increasing severity. Do not equate loud stridor with worst obstruction: sound can diminish as airflow and consciousness decline. Croup is usually a clinical diagnosis. The steeple sign is neither required nor sufficiently sensitive or specific to justify routine neck radiography.
A single dose of dexamethasone is the evidence-based corticosteroid cornerstone. Nebulised adrenaline produces rapid temporary improvement in moderate or severe croup and must be followed by observation while steroid takes effect. Oxygen treats hypoxaemia, not the oedema itself. Humidified air has not shown consistent benefit, steam can burn, salbutamol does not reverse subglottic swelling and antibiotics are not indicated for uncomplicated viral disease. Keep the child calm and avoid unnecessary procedures.
Drooling, dysphagia, toxic appearance, tripod posture and little cough point toward epiglottitis; high fever, toxicity, secretions and poor adrenaline response suggest bacterial tracheitis; sudden choking and unilateral findings suggest foreign body. Facial swelling, urticaria and shock point toward anaphylaxis. In suspected epiglottitis, do not force throat examination outside a controlled airway setting. Recurrent or atypical-age croup merits structural evaluation. The examination answer should combine severity, treatment and disposition: steroid for all hospital-presenting severity groups, adrenaline plus monitoring for significant obstruction, and early expert airway help for exhaustion or inadequate response.
Frequently Asked Questions
Why should a distressed child with croup be kept calm during assessment?
Crying and struggling increase airflow demand and can worsen dynamic obstruction through an already narrowed upper airway. Let the child sit with a caregiver, observe before touching and avoid unnecessary needles, masks or throat examination. Calm handling is not passive care: it occurs alongside rapid severity assessment, preparation of steroid and adrenaline when indicated, and early senior airway support if fatigue or poor air entry appears.
Does improvement after nebulised adrenaline mean a child can go home immediately?
No. Nebulised adrenaline acts quickly but its clinical effect is temporary and generally wanes within about two hours. The child needs reassessment and observation for the period required by the local protocol, with sustained absence of stridor at rest, comfortable breathing and adequate intake before discharge. Repeated doses, rebound symptoms, oxygen need, poor access or diagnostic uncertainty favour admission or transfer.
When should apparent croup be reconsidered as epiglottitis or bacterial tracheitis?
Reconsider the diagnosis with toxic appearance, high fever, drooling, dysphagia, tripod posture, muffled voice, thick secretions, little barking cough or poor response to appropriate croup therapy. Epiglottitis requires calm handling and a controlled expert airway without forced throat examination. Bacterial tracheitis may require airway clearance and intravenous antibiotics. Both need urgent senior paediatric, anaesthetic and ENT involvement.
Are steam inhalation and antibiotics useful treatments for uncomplicated viral croup?
Routine antibiotics do not treat viral croup, and humidified air has not shown reliable improvement in severity. Steam also creates a preventable burn risk. Comfort, a recommended corticosteroid dose, nebulised adrenaline for significant obstruction, oxygen when hypoxaemic and appropriate observation are the evidence-based priorities. Antibiotics belong only in a separate bacterial diagnosis, selected through the relevant clinical pathway.
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