--- title: "Signs in ASOM & Acute Mastoiditis | Cartwheel Sign, Lighthouse Sign, Ironed Out Mastoid & Reservoir Sign" description: "ENT notes on signs in ASOM & Acute Mastoiditis - Cartwheel Sign, Lighthouse Sign, Ironed Out Appearance of Mastoid & Reservoir Sign." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/acute-mastoiditis-asom-signs-cartwheel-reservoir-lighthouse-ironed-out-mastoid" categories: ["Signs, Syndromes, Triads, and Compilation Lists in ENT", "Otology"] video: "https://www.youtube.com/watch?v=R0bUS-7c-P0" image: "https://media.theentresident.com/og-images/acute-mastoiditis-asom-signs-cartwheel-reservoir-lighthouse-ironed-out-mastoid.png" --- # Signs in ASOM & Acute Mastoiditis | Cartwheel Sign, Lighthouse Sign, Ironed Out Mastoid & Reservoir Sign ENT notes on signs in ASOM & Acute Mastoiditis - Cartwheel Sign, Lighthouse Sign, Ironed Out Appearance of Mastoid & Reservoir Sign. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=R0bUS-7c-P0 ## Signs in ASOM & Acute Mastoiditis Several classical signs are associated with **Acute Suppurative Otitis Media (ASOM)** and **Acute Mastoiditis**. In this post, we will discuss: * Cartwheel Sign * Lighthouse Sign * Ironed Out Appearance of Mastoid * Reservoir Sign --- ### Cartwheel Sign #### 📌 Type of Sign 👉 Clinical Sign seen during **Otoscopic examination**. #### 🔍 What is the Sign? Cartwheel Sign refers to a **congested tympanic membrane with a leash of blood vessels along the handle of the malleus and at the periphery of the tympanic membrane**. Seen in **Acute Suppurative Otitis Media**. #### 📍 Stage of ASOM 👉 **Stage of Pre suppuration** > Why is the Cartwheel appearance seen in the stage of pre suppuration in ASOM? > What are the stages of ASOM? #### 🎡 Why is it Called Cartwheel Sign? The radially oriented congested vessels resemble **the spokes of a cartwheel**, hence the name **Cartwheel Sign**. --- ### Lighthouse Sign #### 📌 Type of Sign 👉 Clinical Sign seen during **Otoscopy**. #### 📌 Also Known As 👉 Pulsatile Otorrhea #### 🔍 What is the Sign? Lighthouse Sign refers to **pus coming out under pressure through a small pinhole perforation of the tympanic membrane**, in synchrony with the arterial pulse. #### Seen In 1- **Acute Suppurative Otitis Media** - In the transitory phase from the stage of suppuration to the stage of early resolution, when the tympanic membrane perforates 2- **Acute Mastoiditis** #### 🧠 Why Does it Occur? * Pus collects in the middle ear and mastoid * Pus comes out under pressure through the pinhole perforation * Vascular pulsations within the middle ear make the discharge **pulsatile** * The discharge reflects light **intermittently** as it comes out #### 🚨 Why is it Called Lighthouse Sign? The tiny perforation emits pulsatile discharge intermittently, resembling **a lighthouse beam flashing intermittently**, hence the name **Lighthouse Sign**. --- ### Ironed Out Appearance of Mastoid #### 📌 Type of Sign 👉 Clinical Sign seen during **Examination of the mastoid**. #### 🔍 What is the Sign? Ironed Out Appearance refers to a **smooth, shiny, flattened appearance of the skin over the mastoid region, with loss of the normal bony contour**. Seen in **Acute Mastoiditis**. > What does a normal mastoid feel on palpation? #### 🧠 Why Does it Occur? Infection starts in the middle ear → Spreads to the mastoid air cells → Pus breaks through the **mastoid cortex** → **Periosteitis** and **subperiosteal pus collection** → Thickened periosteum → Overlying skin becomes **stretched, shiny and swollen** #### 👔 Why is it Called Ironed Out Appearance? The mastoid appears **flat, smooth and polished**, like cloth that has been ironed, hence the name **Ironed Out Appearance**. --- ### Reservoir Sign #### 📌 Type of Sign 👉 Clinical Sign seen during **Otoscopy**. #### 🔍 What is the Sign? Reservoir Sign refers to **immediate refilling of the external auditory canal with pus or discharge, as soon as it is suctioned and cleared**. Seen in **Acute Mastoiditis**. #### 🧠 Why Does it Occur? * Pus accumulates in the mastoid and middle ear * There is **continuous pus production** * Suctioning cannot keep up with the rate of pus production * Pus continuously drains into the external auditory canal #### 🪣 Why is it Called Reservoir Sign? The mastoid and middle ear act like **a reservoir of pus**, which keeps spilling into the external auditory canal and refilling it, hence the name **Reservoir Sign**. > What are some signs seen in Acute Mastoiditis? --- ### ⭐ High Yield Rapid Revision Table | Sign | Type | Finding | Seen In | | --- | --- | --- | --- | | Cartwheel Sign | Clinical | Congested tympanic membrane with radiating blood vessels | ASOM (Stage of Pre suppuration) | | Lighthouse Sign | Clinical | Pulsatile pus through a pinhole perforation | ASOM (Suppuration → Early resolution), Acute Mastoiditis | | Ironed Out Mastoid | Clinical | Smooth, shiny, flattened skin over the mastoid | Acute Mastoiditis | | Reservoir Sign | Clinical | External auditory canal refills with pus immediately after suctioning | Acute Mastoiditis | --- ### 🧠 Viva Pearls * Cartwheel Sign is seen in the stage of pre suppuration of ASOM. * In the Cartwheel Sign, congested vessels radiate from the handle of the malleus like the spokes of a cartwheel. * Lighthouse Sign is also known as pulsatile otorrhea. * Lighthouse Sign is seen in ASOM and acute mastoiditis. * In ASOM, the Lighthouse Sign is seen in the transitory phase from suppuration to early resolution. * Ironed Out Appearance of the mastoid is due to subperiosteal pus collection and periostitis. * A normal mastoid feels pitted on palpation. * Reservoir Sign is immediate refilling of the external auditory canal with pus after suctioning. * Reservoir Sign is due to continuous pus production in the mastoid and middle ear. * Obliteration of the retroauricular sulcus and sagging of the posterosuperior meatal wall are also seen in acute mastoiditis. --- ## About This Note This free ENT note on Signs in ASOM & Acute Mastoiditis | Cartwheel Sign, Lighthouse Sign, Ironed Out Mastoid & Reservoir Sign was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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