<prompt> A 4-year-old child presents to the emergency depament with high grade fever, respiratory difficulty and noisy breathing. On examination. X ray of his neck is shown below. The most probable diagnosis is?Recurrent papillomatosisCroupEpiglottitisTonsillitis  <response>: The given clinical picture along with the X-ray shows thumb sign , this finding suggests a diagnosis of Acute Epiglottitis. Thumb sign is a term also used in other conditions: Thumb sign Marfan disease also known as Steinberg sign: a clinical test in which the tip of the thumb is visible medial to the little finger when it is clasped in the clenched hand. Thumb sign chordoma: a radiological sign showing a clival tumour projection indenting the pons. 