<prompt> Thumb sign in lateral X-ray of neck seen inAcute EpiglottitisSaccular cystVallecular cystCa Epiglottis  <response>: ACUTE EPIGLOTTITIS SYN. SUPRAGLOTTIC LARYNGITIS It is an acute inflammatory condition confined to supraglottic structures, i.e. epiglottis, aryepiglottic folds and arytenoids. There is marked oedema of these structures which may obstruct the airway. AETIOLOGY :- It is a serious condition and affects children of 2-7 years of age but can also affect adults. H. influenzae B is the most common organism responsible for this condition in children. CLINICAL FEATURES :- 1. Onset of symptoms is abrupt with rapid progression. 2. Sore throat and dysphagia are the common presenting symptoms in adults. 3. Dyspnoea and stridor are the common presenting symptoms in children. They are rapidly progressive and may prove fatal unless relieved. 4. Fever may go up to 40degC. It is due to septicaemia. Patients condition may rapidly deteriorate. CLINICAL EXAMINATION :- 1. Depressing the tongue with a tongue depressor may show red and swollen epiglottis. Indirect laryngoscopy may show oedema and congestion of supraglottic structure. 2. Lateral soft tissue X-ray of neck may show swollen epiglottis thumb sign. Ref:- Dhingra; pg num:-289 