Acute Epiglottitis

Acute epiglottitis (supraglottitis) is a rapidly progressive, life-threatening inflammation of the epiglottis and adjacent supraglottic structures that can cause sudden, complete upper-airway obstruction. It is a true ENT and paediatric emergency where airway comes before everything else — including investigation. For NEET PG it is a perennial favourite because of its sharp contrast with acute laryngotracheobronchitis (croup).

Definition and classification

Acute epiglottitis is an acute inflammatory oedema of the supraglottic larynx — the epiglottis, aryepiglottic folds, arytenoids, and false cords. Because the inflammation is rarely confined to the epiglottis alone, the more accurate term is supraglottitis. The vocal cords and subglottis are characteristically spared, which is why the voice is muffled ("hot-potato voice") rather than hoarse, and why stridor is relatively late and inspiratory.

It is classically a disease of children aged 2–6 years, but the epidemiology has shifted markedly after the introduction of the Hib (Haemophilus influenzae type b) conjugate vaccine, and the disease is now increasingly seen in adults (mean age ~45 years), often with a more indolent course.

High-yield: Epiglottitis = supraglottic disease (muffled voice, drooling, tripod posture). Croup = subglottic disease (barking cough, hoarse voice). This anatomical split explains nearly every clinical difference asked in the exam.

Feature	Acute epiglottitis	Croup (laryngotracheobronchitis)
Site	Supraglottis	Subglottis / trachea
Classic organism	H. influenzae type b	Parainfluenza virus (type 1)
Age	2–6 yr (also adults now)	6 months–3 yr
Onset	Hours (fulminant)	1–3 days (gradual, preceded by URTI)
Toxaemia	Marked, toxic, high fever	Mild, low-grade fever
Cough	Absent or minimal	Barking ("seal-like")
Voice	Muffled ("hot potato")	Hoarse
Drooling	Present (cannot swallow)	Absent
Posture	Tripod / sniffing, sitting up	Comfortable lying down
Cough	Usually absent	Characteristic barking
X-ray	"Thumb-print" sign (lateral neck)	"Steeple" sign (AP neck)
Stridor	Soft, inspiratory, late	Loud, inspiratory ± biphasic

Etiology and pathophysiology

The historically classic and most-tested organism is Haemophilus influenzae type b (Hib), a Gram-negative coccobacillus. Before universal Hib vaccination, Hib caused the overwhelming majority of paediatric cases. After conjugate vaccination programmes (Hib introduced into India's Universal Immunisation Programme as part of the pentavalent vaccine), paediatric Hib epiglottitis has become rare, and the disease has shifted towards older children and adults with a wider organism spectrum.

Other causative organisms include:

• Streptococcus pneumoniae
• Streptococcus pyogenes (Group A strep) and other beta-haemolytic streptococci
• Staphylococcus aureus (including MRSA)
• H. influenzae non-type-b and non-typeable strains
• Viral and fungal causes (e.g. Candida in immunocompromised, HSV)
• Non-infective: thermal injury (scalding liquids, smoke, crack-cocaine inhalation), caustic ingestion, foreign body, post-radiotherapy.

Pathophysiology: Bacteraemic seeding or direct mucosal invasion produces intense inflammatory oedema of the loose submucosal tissue on the lingual surface of the epiglottis. Because this tissue plane is loose and distensible, oedema accumulates rapidly, curling the epiglottis posteriorly and inferiorly over the laryngeal inlet like a swollen "cherry". The aryepiglottic folds swell and prolapse medially. The net effect is progressive narrowing of the supraglottic airway. Crucially, any added insult — crying, agitation, gagging, forced supine positioning, or instrumentation (tongue depressor/laryngoscope) — can precipitate laryngospasm and complete, fatal obstruction.

Bacteraemia / mucosal invasion → intense supraglottic oedema
→ "cherry-red" swollen epiglottis curls over inlet
→ progressive airway narrowing → triggered laryngospasm
→ COMPLETE OBSTRUCTION → asphyxia / death

Clinical features

The hallmark is a child who looks toxic and frightened with rapid (hours) onset of:

• High fever (often >39 °C)
• Severe odynophagia / dysphagia — refuses to eat or drink
• Drooling of saliva (cannot/will not swallow)
• Muffled "hot-potato" voice (not hoarse)
• Soft inspiratory stridor (a late, ominous sign)
• Tripod / "sniffing" position — sitting forward, neck extended, mouth open, tongue protruding, to maximise airway diameter
• Restlessness, anxiety, air hunger; tachycardia and tachypnoea
• Cough is typically absent (contrast with croup)

The classic mnemonic for the cardinal features:

The "4 Ds" of epiglottitis: Dysphagia, Drooling, Dysphonia (muffled voice), Distress (respiratory).

In adults, presentation is often less dramatic — sore throat out of proportion to oropharyngeal findings, odynophagia, and a normal-looking oropharynx are the clue. A patient whose throat pain is severe but whose oropharynx looks unremarkable should raise suspicion of supraglottic pathology.

High-yield: A toxic child sitting upright, drooling, with muffled voice and soft stridor = epiglottitis until proven otherwise. Do NOT lay the child flat and do NOT examine the throat with a tongue depressor — either may trigger fatal obstruction.

Diagnosis and investigation of choice

Diagnosis is clinical, and securing the airway takes priority over confirmatory tests. The single most important rule:

High-yield: In a child with suspected epiglottitis, do NOT perform indirect laryngoscopy / throat examination / venepuncture / X-ray in the casualty without airway readiness — agitation can precipitate complete obstruction. The child must be kept calm, upright, with a parent, and taken to the operating theatre where intubation and tracheostomy facilities are available.

Definitive diagnosis is made by direct visualisation of the epiglottis — done in the controlled environment of the operating theatre by an experienced anaesthetist/ENT surgeon, ideally as part of a planned intubation under inhalational (gas) induction with the surgeon scrubbed for emergency tracheostomy. The epiglottis appears cherry-red and swollen.

Imaging — the lateral neck soft-tissue X-ray:

• The "thumb-print" sign (or "thumb sign") — a swollen, rounded epiglottis resembling an adult's thumb — is the classic radiological finding.
• Loss/widening of the vallecula ("vallecula sign"), thickened aryepiglottic folds, and ballooning of the hypopharynx may be seen.

High-yield: X-ray (thumb-print sign) is only acceptable in a stable, cooperative patient with monitoring; the child must NOT be sent unaccompanied to a remote radiology suite. Airway security always trumps the radiograph. In a clearly toxic, struggling child, skip the X-ray and go straight to theatre.

Other investigations (obtained after the airway is secured): blood cultures (positive in a significant proportion of Hib cases), epiglottic surface cultures, FBC (leucocytosis with left shift), CRP, and arterial/venous blood gas.

Sign	Modality	Finding	Disease
Thumb-print sign	Lateral neck X-ray	Swollen rounded epiglottis	Epiglottitis
Steeple sign	AP neck X-ray	Subglottic tapering	Croup
Vallecula sign	Lateral neck X-ray	Obliterated vallecula	Epiglottitis

Management and drug of choice

Management follows a strict sequence — airway first, antibiotics second.

Stepwise approach:

1. Do not disturb the child. Keep calm, upright, with the parent. Avoid cannulation, throat exam, and supine positioning. Administer humidified oxygen (blow-by) if tolerated. Call the most experienced anaesthetist and ENT surgeon.
2. Secure the airway in theatre. Gaseous (inhalational) induction with the child sitting / in the position of comfort, breathing spontaneously (sevoflurane in oxygen). Avoid muscle relaxants until the airway is visualised, because paralysis can collapse a marginal airway. Intubate with an endotracheal tube smaller than predicted for age.
3. Be ready for surgical airway. Equipment for rigid bronchoscopy and emergency tracheostomy must be open and the ENT surgeon scrubbed. If intubation fails → tracheostomy.
4. Antibiotics — drug of choice: intravenous third-generation cephalosporin — ceftriaxone or cefotaxime (covers Hib including beta-lactamase producers, pneumococcus, streptococci). Add an anti-staphylococcal agent (e.g. vancomycin) where MRSA is a concern. Continue 7–10 days, switching to oral once stable.
5. Adjuncts: IV fluids, antipyretics (paracetamol), and corticosteroids (dexamethasone) are often given to reduce oedema (evidence modest but widely used). Nebulised adrenaline may buy time in impending obstruction as a temporising measure.
6. Extubation usually after 2–3 days when fever settles and a leak develops around the tube / epiglottic swelling subsides on re-look.

High-yield: Drug of choice = IV ceftriaxone (third-generation cephalosporin). Old answer "chloramphenicol + ampicillin" is now obsolete due to resistance.

Prophylaxis and prevention:

• Hib conjugate vaccine has dramatically reduced incidence — the single most important preventive measure. In India it is given as part of the pentavalent vaccine (DTwP + Hib + HepB) at 6, 10, and 14 weeks.
• Rifampicin prophylaxis for close/household contacts of an index Hib case (especially households with unimmunised children <4 years).

High-yield: Hib vaccine has shifted epiglottitis from a paediatric Hib disease to an adult disease with mixed organisms. Rifampicin is the chemoprophylaxis for contacts of invasive Hib disease.

Complications

• Complete airway obstruction and respiratory arrest — the immediate and most feared complication; the reason instrumentation is forbidden.
• Hypoxic-ischaemic brain injury / death following sudden obstruction.
• Epiglottic abscess — a localised collection on the lingual surface, may need drainage.
• Aspiration pneumonia and post-obstructive pulmonary oedema (negative-pressure pulmonary oedema after relief of obstruction).
• Bacteraemic spread of Hib → meningitis, septic arthritis, cellulitis, pneumonia, otitis media.
• Complications of the secured airway — accidental extubation, tube blockage, tracheostomy-related issues.
• Cervical cellulitis / deep neck space spread in adults.

Key differentials

The presentation of stridor + respiratory distress in a child has several mimics; distinguishing them is the most heavily tested aspect.

Condition	Key distinguishing feature
Croup	Barking cough, hoarse voice, gradual onset, steeple sign, comfortable supine
Bacterial tracheitis	Toxic child, brassy cough, thick purulent tracheal secretions; S. aureus; subglottic
Retropharyngeal abscess	Neck stiffness/extension, bulge on posterior pharyngeal wall, widened prevertebral soft tissue on X-ray
Peritonsillar abscess (quinsy)	Trismus, uvular deviation, unilateral tonsillar swelling, older child/adult
Foreign body (laryngeal/tracheal)	Sudden choking, witnessed event, unilateral signs
Diphtheria	Grey adherent pseudomembrane, bull-neck, low-grade fever, unimmunised
Angioedema / anaphylaxis	Rapid lip/tongue swelling, urticaria, allergen exposure, no fever
Laryngomalacia	Neonate/infant, positional stridor, improves prone, no toxaemia

High-yield: Bacterial tracheitis is an important croup-mimic — a toxic child with stridor who fails to respond to croup treatment; organism is usually S. aureus, and it is a leading cause of airway obstruction in vaccinated populations where Hib epiglottitis has declined.

Recently asked / exam angle

NEET PG and INI-CET style questions tend to cluster around a few reliable themes:

• "Thumb-print sign" on lateral neck X-ray → answer: acute epiglottitis (and "steeple sign" → croup). Image-based questions are common.
• The classic organism is Hib, but the examiner may add "in a vaccinated population" to make you choose S. pneumoniae / S. aureus / streptococci.
• What is contraindicated? → Examining the throat with a tongue depressor / indirect laryngoscopy in the casualty / lying the child supine. A frequent single-best-answer trap.
• First step in management of a toxic, drooling child → secure the airway in the operating theatre (do not investigate first).
• Drug of choice → IV ceftriaxone / cefotaxime (reject chloramphenicol-ampicillin as outdated).
• Position of comfort → tripod / sniffing position; muffled "hot-potato" voice vs hoarse voice of croup.
• Chemoprophylaxis of contacts → rifampicin.
• A classic clinical-vignette pairing: contrast croup vs epiglottitis features in a single question — know the table cold.
• Site of disease: epiglottitis = supraglottic; croup = subglottic; bacterial tracheitis = trachea/subglottic.

High-yield: If a question offers "lateral soft-tissue neck radiograph" as an option for a struggling, toxic child — the safer/correct management answer is usually to secure the airway first, not to image. Examiners reward airway-first thinking.

Rapid revision

1. Acute epiglottitis = supraglottitis; the vocal cords are spared (muffled voice, not hoarse).
2. Classic organism = Haemophilus influenzae type b (Hib); now rare after vaccination, so think pneumococcus/strep/staph too.
3. Age 2–6 years classically; increasingly an adult disease post-Hib vaccine.
4. Cardinal features = 4 Ds: Dysphagia, Drooling, Dysphonia, Distress + tripod posture, high fever, toxaemia.
5. Onset is fulminant (hours) — contrast with the gradual onset of croup.
6. Cherry-red swollen epiglottis on direct visualisation (done only in theatre).
7. Radiology: thumb-print sign on lateral neck X-ray (croup = steeple sign on AP view).
8. NEVER depress the tongue, do indirect laryngoscopy, or lay the child flat — risk of fatal obstruction.
9. Management = airway first → gaseous induction, sitting, intubate with a smaller-than-predicted tube; keep tracheostomy ready.
10. Drug of choice = IV ceftriaxone / cefotaxime (3rd-gen cephalosporin); add vancomycin if MRSA suspected.
11. Prevention = Hib conjugate (pentavalent) vaccine; contact chemoprophylaxis = rifampicin.
12. Croup-mimic to remember = bacterial tracheitis (S. aureus, brassy cough, fails croup therapy).