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EN4.41 | Benign Inflammatory Paralytic Laryngeal Disorders — SDL Guide (Part 2)

Examination and Investigation of Benign and Inflammatory Laryngeal Disease

The investigation strategy for non-malignant laryngeal disease is tailored to the clinical context — and choosing the wrong investigation, or the wrong investigation sequence, can be as dangerous as choosing the wrong treatment. In the stable outpatient with chronic hoarseness, laryngoscopy is the cornerstone and can be performed safely in the clinic. In the child with stridor and suspected epiglottitis, the investigation sequence is fundamentally different: the correct order is clinical diagnosis first, then airway secured under controlled conditions, and only then confirmatory radiology. Attempting a lateral neck X-ray before the airway is secured in a child with suspected epiglottitis is a dangerous error — the child can obstruct completely while lying still for the X-ray. This principle — that in laryngeal emergencies the airway takes priority over the investigation — must be internalised before examining the details of the investigative toolkit.

For the stable patient, laryngoscopy provides both diagnosis and functional assessment. Indirect laryngoscopy (IDL) and flexible fibre-optic nasolaryngoscopy (FFNL) provide the primary visual diagnosis for benign structural lesions and chronic inflammatory conditions. Key findings on laryngoscopy include:
- Nodules: bilateral whitish thickenings at the anterior one-third/posterior two-thirds junction.
- Polyp: unilateral mass (pedunculated or sessile, red or translucent) at the same junction.
- Reinke's oedema: bilateral pale, grape-like, translucent swellings across the entire cord surface.
- Granuloma: pale, smooth swelling at the posterior vocal process of the arytenoid.
- Papilloma: exophytic, frond-like, pink or white warty masses on the cord surface, which may be multifocal.
- Acute laryngitis: diffuse erythema and oedema of the vocal cords, with a mucous secretion.
- Chronic laryngitis: thickening, irregular surface, erythema; leukoplakia appears as a white patch.
- Epiglottitis: a red, swollen, cherry-like epiglottis — but remember, laryngoscopy in a suspected child case must be performed only in a controlled setting (anaesthetic room) with airway equipment ready.

Radiological investigations:
- Lateral neck X-ray: 'thumb sign' in epiglottitis (swollen, thumb-shaped epiglottis).
- AP neck/chest X-ray: 'steeple sign' in croup (subglottic narrowing, loss of normal shouldering).
- These signs are helpful but airway management should not be delayed for radiology if the airway is compromised.

Microlaryngoscopy under general anaesthesia (MLB/DL) is used for: tissue biopsy (papilloma, leukoplakia); excision of polyp, granuloma, papilloma; assessment of lesions not adequately seen on indirect examination.

Voice analysis — maximum phonation time, acoustic analysis — provides objective baseline assessment and monitors treatment response for benign lesions.

Additional investigations:
- Throat swab/culture: for diphtheria (modified Eaton's agar / Loeffler's serum slope); Schick test for susceptibility (historical, rarely used now).
- Laryngeal biopsy: mandatory when leukoplakia is identified on laryngoscopy in a smoker — the only way to distinguish dysplasia from carcinoma in situ.
- HPV typing: on excised papilloma tissue to guide prognosis (HPV 11 has higher recurrence and rare malignant transformation risk than HPV 6).

Diagnosis and Clinical Differentiation

Clinical differentiation of laryngeal conditions is built on integrating the patient's age, acuity of onset, immunisation history, laryngoscopic appearance, and radiology. The four main infectious conditions causing acute laryngeal distress have sufficiently distinct profiles that a systematic review of the clinical features permits confident diagnosis in most cases.

The differential diagnosis of the acute stridor child is the most clinically critical distinction in this SDL. Epiglottitis and croup are both causes of childhood stridor but differ in almost every clinical feature. Epiglottitis typically affects a slightly older child (1–7 years in the pre-Hib vaccination era; now more commonly adults), has an abrupt onset with high fever, looks toxic, cannot swallow saliva, and sits in the tripod posture. Croup affects younger children (6 months–5 years), has a preceding viral URI, produces the characteristic barking cough, and the child is relatively less toxic-appearing. Diphtheria is now rare in vaccinated populations but must be considered in any child presenting with stridor, low-grade fever, and a grey pharyngeal/laryngeal membrane, particularly if incompletely vaccinated.

Condition	Age	Pathogen	Key symptom	Key sign/X-ray	Management priority
Acute laryngitis	Any	Viral (rhinovirus, influenza)	Hoarseness ± URI	IDL: red oedematous cords	Voice rest, symptomatic
Acute epiglottitis	1–7 yr (Hib era); adults now	H. influenzae b; streptococcus	Drooling, toxic, hot-potato voice	Lateral X-ray: thumb sign	SECURE AIRWAY FIRST, then IV ceftriaxone
Croup	6 months–5 yr	Parainfluenza type 1	Barking cough, inspiratory stridor	AP X-ray: steeple sign	Dexamethasone ± nebulised adrenaline
Diphtheria	Unvaccinated child/adult	Corynebacterium diphtheriae	Progressive stridor, bull neck	Grey pseudomembrane; bleeds on removal	Antitoxin + penicillin/erythromycin

For benign vocal cord lesions, differentiating features are: nodules (bilateral, symmetric, junction, professional voice user, no sudden onset), polyp (unilateral, single trauma event, haemorrhagic or translucent), Reinke's oedema (bilateral, entire cord, smoker, low-pitched voice), granuloma (posterior arytenoid, reflux history or recent intubation, tends to recur after excision). Laryngeal paralysis is recognised by asymmetric or absent cord movement on laryngoscopy with a breathy voice (unilateral) or stridor with relatively preserved voice quality (bilateral).

Principles of Management

The management of benign and inflammatory laryngeal conditions follows the same fundamental principle as all laryngeal management — identify the diagnosis, address reversible causes, reserve surgery for lesions that are either structural (requiring excision) or have failed conservative treatment. The critical additional principle for inflammatory emergencies is: secure the airway before everything else.

The sequencing of interventions matters enormously. A clinician who attempts IV cannulation, blood cultures, or a throat examination before securing the airway in acute epiglottitis may lose the patient. Conversely, a clinician who reaches for the scalpel to excise vocal cord nodules before a course of voice therapy will produce a patient with recurrent nodules on a scarred cord with a permanently worse voice. The treatment sequence is as diagnostically important as the treatment choice.

Benign structural lesions:
- Vocal cord nodules: voice therapy (speech-language pathologist) for 3–6 months is mandatory first-line; the majority resolve. Microlaryngoscopic excision (cold steel or CO2 laser, preserving Reinke's space) is reserved for nodules failing conservative treatment. Recurrence is common if vocal hygiene is not corrected.
- Vocal cord polyp: microlaryngoscopy and excision; specimen to histopathology. Anti-reflux therapy concurrent with surgery if reflux is contributing. Post-operative voice therapy.
- Reinke's oedema: smoking cessation (mandatory, often produces partial improvement); treatment of hypothyroidism; phonomicrosurgery (cordotomy, evacuation, mucosal trimming — never strip the entire cord).
- Contact granuloma: anti-reflux therapy with proton pump inhibitors for 3–6 months (at least) as primary treatment; voice therapy; surgical excision avoided as first-line due to high recurrence — reserved for granuloma causing airway compromise.
- Laryngeal papilloma: CO2 laser ablation or microdebrider excision under microlaryngoscopy; multiple procedures usually required for juvenile form; adjuvant treatments (cidofovir injection, bevacizumab infusions) for aggressive juvenile recurrent respiratory papillomatosis.

Inflammatory conditions:
- Acute laryngitis: voice rest, steam inhalation, analgesics, hydration; antibiotics not indicated. Systemic corticosteroids for professional voice users with a performance commitment.
- Acute epiglottitis (airway emergency): summon senior anaesthetist immediately; do NOT examine throat; bring to theatre/anaesthetic room; controlled RSI (rapid sequence induction) and orotracheal intubation (tracheostomy if intubation fails); IV ceftriaxone or co-amoxiclav after airway secured; ICU admission; extubate when epiglottic swelling resolves (usually 48–72 hours).
- Croup: mild (barking cough, no stridor at rest) = oral dexamethasone 0.15–0.6 mg/kg, discharge; moderate = nebulised adrenaline (1:1000, 0.5 mL/kg up to 5 mL) + dexamethasone + observation; severe = intubation.
- Diphtheria: diphtheria antitoxin IM/IV urgently (do not wait for culture confirmation — antitoxin neutralises unbound toxin only); penicillin G IV for 14 days (or erythromycin); isolation; airway management as required; monitor for myocarditis (ECG) and neuropathy.
- Chronic laryngitis/leukoplakia: smoking cessation, anti-reflux therapy; biopsy all white lesions; surveillance laryngoscopy for dysplasia; CO2 laser vaporisation for dysplastic lesions.

Laryngeal paralysis: treat the underlying cause; spontaneous recovery possible in 6–12 months (observe); injection laryngoplasty (temporary medialization with Gelfoam/hyaluronic acid) for early symptomatic relief or aspiration risk; Type I thyroplasty for permanent medialization in persistent unilateral palsy; bilateral palsy with airway compromise = urgent tracheostomy, then staged glottoplasty/arytenoidectomy.

Self-Assessment: Benign and Inflammatory Laryngeal Disorders

Use these clinical scenarios to consolidate your understanding of the three categories covered in this SDL. For each scenario, identify the most likely diagnosis, state the single most important management step, and explain your reasoning. The scenarios are designed to test differential diagnosis at the key decision points — the stable hoarse adult, the child with acute stridor, and the recurrent laryngeal lesion.

Scenario A: A 35-year-old female non-smoker, who works as a fitness instructor, presents with hoarseness for four months. On IDL, she has bilateral smooth whitish thickenings at the midpoint of both vocal cords. There is no leukoplakia and no impaired mobility. What is the diagnosis and the correct first-line treatment?

Scenario B: A 2-year-old child presents at 11 PM with a three-day history of runny nose, a sudden-onset barking cough, and moderate inspiratory stridor. Temperature 37.8°C. The child is sitting up but is not drooling. AP neck X-ray shows the steeple sign. What is the diagnosis and immediate management?

Scenario C: A 5-year-old unvaccinated child presents with two days of sore throat, low-grade fever, neck swelling, and now stridor. On examination, there is a grey-white membrane on the posterior pharyngeal wall that bleeds on attempted removal. What is the working diagnosis and what must be given immediately before culture results?

Key recall questions:
- Name the commonest benign laryngeal tumour and its causative HPV types.
- What is the pathognomonic X-ray sign of acute epiglottitis, and on which view?
- What is the pathognomonic X-ray sign of croup, and on which view?
- State the single most important management rule in suspected acute epiglottitis.
- What is the primary treatment for a laryngeal contact granuloma?

Answers:
- Laryngeal papilloma; HPV types 6 and 11.
- 'Thumb sign' (swollen epiglottis); lateral neck X-ray.
- 'Steeple sign' (subglottic narrowing); AP neck/chest X-ray.
- Do NOT examine the throat — secure the airway first under controlled anaesthesia.
- Anti-reflux therapy (proton pump inhibitors) as primary treatment; surgery reserved for airway compromise.