Cart-wheel appearance of tympanic membrane in ASOM is due to -

Ans. is 4c' i.e., Congested blood vessels along malleusStages ofASQMo ASOM runs through the following stages and therefore presentation depends upon the stage : -1) Stage of tubal occlusion (Eustachian tube obstruction)Edema and hyperaemia of nasopharyngeal end of Eustachion tube blocks the tube, leading to absorption of air and negative intratympanic pressure.There is feeling of discomfort and mild hearing loss (conductive) with pink retracted tympanic membrane.Stage of presuppuration (Early infection)There is collection of inflammatory exudate behind the tympanic membrane.There is marked Throbbing earache, hearing loss, tinnitus and fever.Tympanic membrane is congested. Leash of blood vessels appear along the handle of malleus and at the periphery of tympanic membrane imparting it a Cart-wheel appearance.Stage of suppuration (suppurative stage)There is collection of frank pus in the middle ear.Patient has excruciating earache, hearing loss, and constitutional symptoms like high grade fever.Tympanic membrane is red and bulging with loss of landmarks.Stage of resolution (Resolution stage)The tympanic membrane ruptures with release ofpus and subsidence of symptoms.Earache is relieved, fever comes down and child feels better.