--- title: "Omega Sign vs Thumb Sign | Signs in Laryngomalacia & Acute Epiglottitis" description: "ENT notes on Omega Sign seen in Laryngomalacia & Thumb Sign seen in Acute Epiglottitis." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/omega-sign-laryngomalacia-thumb-sign-epiglottitis" categories: ["Signs, Syndromes, Triads, and Compilation Lists in ENT", "Larynx and Trachea"] video: "https://www.youtube.com/watch?v=UL8CAyZWrKI" image: "https://media.theentresident.com/og-images/omega-sign-laryngomalacia-thumb-sign-epiglottitis.png" --- # Omega Sign vs Thumb Sign | Signs in Laryngomalacia & Acute Epiglottitis ENT notes on Omega Sign seen in Laryngomalacia & Thumb Sign seen in Acute Epiglottitis. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=UL8CAyZWrKI ## Omega Sign & Thumb Sign Two classical signs are seen in laryngeal disorders, and are commonly confused with each other. In this post, we will discuss: * Omega Sign * Thumb Sign --- ### Omega Sign #### 📌 Type of Sign 👉 Clinical Sign seen during **Laryngoscopy**. #### 🔍 What is the Sign? Omega Sign refers to **inward curling of the aryepiglottic folds, causing the epiglottis to appear omega shaped**. Seen in **Laryngomalacia**. > What is the shape of a normal Epiglottis? #### 🧠 Why Does it Occur? In laryngomalacia, there is a **lack of tautness of the supraglottic cartilages**. * Aryepiglottic folds become **shortened and floppy** * Supraglottic laxity leads to **collapse of the structure during inspiration** * Aryepiglottic folds and epiglottis curl inwards Resulting in the **Omega shaped epiglottis**. #### Ω Why is it Called Omega Sign? The curled up epiglottis resembles the Greek letter **omega (Ω)**, hence the name **Omega Sign**. #### ⚠️ Important MCQ Trap Omega epiglottis is seen in: ✅ Laryngomalacia ❌ Not seen in Epiglottitis ⭐ Omega sign occurs due to a **floppy supraglottis**, not due to infection. > What is the most common cause of stridor in infants? > What is the type of stridor seen in laryngomalacia? > What is the natural course of laryngomalacia? --- ### Thumb Sign #### 📌 Type of Sign 👉 Radiological Sign seen on **Xray Neck (Lateral view)**. #### 🔍 What is the Sign? Thumb Sign refers to **an enlarged, swollen epiglottis appearing as a thumb shaped shadow** on a lateral Xray of the neck. Seen in **Acute Epiglottitis**. #### 🧠 Why Does it Occur? In acute epiglottitis, there is **severe inflammation and edema of the epiglottis and aryepiglottic folds**. The epiglottis becomes **thickened and rounded**. #### 👍 Why is it Called Thumb Sign? The swollen epiglottis resembles **a thumb**, hence the name **Thumb Sign**. > What is the most common causative organism of acute epiglottitis? > What is the Tripod Sign? #### ⚠️ Important Clinical Point ❌ Do **not** perform an aggressive throat examination in a suspected case of epiglottitis. > Why should you not perform a throat examination in a suspected case of epiglottitis? --- ### ⭐ High Yield Rapid Revision Table | Feature | Omega Sign | Thumb Sign | | --- | --- | --- | | Type of Sign | Clinical | Radiological | | Seen On | Laryngoscopy | X-ray Neck (Lateral view) | | Finding | Inward curling of aryepiglottic folds, omega shaped epiglottis | Enlarged, swollen, thumb shaped epiglottis | | Seen In | Laryngomalacia | Acute Epiglottitis | | Cause | Supraglottic laxity (floppy supraglottis) | Inflammation and edema (infection) | --- ### 🧠 Viva Pearls * Omega Sign is seen in laryngomalacia, not in epiglottitis. * Omega Sign is due to inward curling of shortened, floppy aryepiglottic folds. * Omega Sign occurs due to lack of tautness of the supraglottic cartilages. * Laryngomalacia is the most common cause of stridor in infants. * Thumb Sign is a radiological sign seen on a lateral X-ray of the neck. * Thumb Sign is seen in acute epiglottitis. --- ## About This Note This free ENT note on Omega Sign vs Thumb Sign | Signs in Laryngomalacia & Acute Epiglottitis was written by Dr. Mausumi Das and is paired with a corresponding video lecture. Canonical page of this note: https://www.theentresident.com/ent-notes-lectures/omega-sign-laryngomalacia-thumb-sign-epiglottitis When citing or referencing this content, please credit The ENT Resident and link to the canonical page above. ## Related Notes by Category - Signs, Syndromes, Triads, and Compilation Lists in ENT: https://www.theentresident.com/ent-notes-lectures/category/signs-syndromes-triads-lists-in-ent.md - Larynx and Trachea: https://www.theentresident.com/ent-notes-lectures/category/larynx-and-trachea.md ## About The ENT Resident The ENT Resident is an educational website and resource library created by Dr. Mausumi Das (MS ENT) for ENT residents, ENT postgraduates preparing for exams, and MBBS students. Dr. Mausumi Das writes the notes, draws the diagrams, and records the lectures herself. 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