77.CART WHEEL APPEARENCE ON TYMPANIC MEMBRANE

A.ASOM
B.CSOM
C.SUPPURATIVE OTITIS MEDIA
D.OTOSCELOSIS

ANS:ASOM


Stages of A.S.O.M.

1. Stage of Hyperaemia 

Synonym: Stage of tubal occlusion
Mild earache
T.M. retracted in early stage
T.M. congested later stage
Cartwheel appearance: radiating blood vessels from handle of malleus

2. Stage of Exudation 

High fever
Severe earache
Deafness
Marked congestion + bulging of T.M.
Mastoid tenderness
P.T.A.: high frequency conductive deafness
               due to mass effect of pus

Nipple sign (impending perforation)

Localized protrusion of tympanic membrane due to destruction of fibrous layer by continuous pressure of pus

3. Stage of Suppuration 

Symptoms:

Ear discharge (blood-stained  purulent)
Increased deafness
Decreased fever
Decreased earache
Blood stained otorrhoea

Signs & Investigations

Pinhole perforation + otorrhoea
Light house sign: intermittent reflection of light
Decreased mastoid tenderness
High (mass effect) + low frequency (stiffness effect of thick periosteum) Conductive deafness
Clouding of air cells in mastoid X-ray
Light House sign

4. Stage of Coalescent Mastoiditis 


Otorrhoea > 2 weeks, otalgia & deafness
Mastoid reservoir sign: pus fills up on mopping
Sagging of postero-superior canal wall caused by peri-osteitis due to pus in adjacent mastoid antrum
Ironed out appearance of skin over mastoid due to thickened periosteum
Mastoid cavity in X-ray & CT scan