Anatomy and Physiology of the Larynx Tube occupying middle third of the neckOpposite 3rd,4th,5th,6th cervical vertebraeFramework of cartilages, not to allow for collapse with inspirationCartilages are connected by ligaments & membranesLarynx CartilageCartilaginous FrameworkUnpaired 1- Epiglottis Cartilage 2- Thyroid Cartilage 3- Cricoid CartilagePaired 1- Arytenoid Cartilage 2- Corniculate Cartilage 3- Cuniform Cartilage 4- triticeal CartilageEpiglottic cartilage A thin lamina of elastic cartilage forming the central portion of the epiglottis. attached to the thyroid cartilage of the larynx by the thyroepiglottic ligament; it is the structural basis of the epiglottis.Larynx CartilageThyroid cartilage The largest cartilage of the larynx consisting of two laminae fusing anteriorly at an acute angle in the midline of the neck. The point of fusion forms a subcutaneous projection known as the adams apple.Larynx CartilageCarcoid cartilageIt sits just inferior to the thyroid cartilage in the neck, and is joined to it medially by the median cricothyroid ligament and postero-laterally by the cricothyroid joints. Inferior to it are the rings of cartilage around the trachea (which are not continuous - rather they are C-shaped with a gap posteriorly). The cricoid is joined to the first tracheal ring by the cricotracheal ligament, and this can be felt as a more yielding area between the firm thyroid cartilage and firmer cricoid. The posterior part of the cricoid is slightly broader than the anterior and lateral parts, and is called the lamina, while the anterior part is the band; this may be the reason for the common comparison made between the cricoid and a signet ring. Larynx CartilageArytenoids CartilageOne of a pair of small pyramidal cartilages that articulate with the lamina of the cricoid cartilage. The corresponding vocal ligament and several muscles are attached to it. larynx cartilageElastic TissueThe elastic tissue of the larynx consists of two main parts:(1) the quadrangular membrane of the supraglottic larynx;and(2)the thicker conus elasticus and vocal ligaments of the glottic and infraglottic larynxMuscles of the LarynxExtrinsic1- Thyrohyoid Muscles2- Sternothyroid MusclesRaise and lower the larynx during deglutitionAccording to the functions:1- Raise the larynx : Thyrohyoid Muscles, Mylohyoid muscle, Digastric muscle, Stylohyoid muscle2- Lower the larynx :Sternothyroid Muscles,Sternohyoid M, supraomohyoid M, pharyngeal constrictor muscle Muscles of the LarynxIntrinsic-All paired except the transverse arytenoid-Abductor: Post. Crico-arytenoid-Adductors: Lat. Crico-arytenoid, interarytenoid & thyroarytenoid-Tensors: Internal part of thyroarytenoid-Cricothyroid, adductor & tensorMuscles of the LarynxCavity of the Larynx Laryngeal Cavity: 3 portions Supraglottic portion ; Glottic portion; Infraglottic portion Supraglottic portion:EpiglottisAritenoepiglottic FoldArytenoid areaFalse Vocal Cord Glottic portion: Vocal Cord Fissure of GlottisAnterior Commisure Cavity of the LarynxCavity of the LarynxInfraglottic portion Mucosa of the larynxThe mucosa of the larynx is of two types,ciliated pseudostratified columnar cell(respiratory)epithelium and squamous cell epithelium.Much of the larynx is surfaced by respiratory epithelium.The superior epiglottis,upper aryepiglottic folds,and the free edges of thevocal folds are surfaced by squamous cell epitheliumMucosa of the larynxBeneath this covering epithelium is a variable basement membrane,and separating these two is a layer of loose fibrous stroma.This loose fibrous layer is absent on the true vocal folds,as well as on the laryngeal surface of the epiglottis.The absence of this layer on the posterior of the epiglottis accounts for the more intense swelling of the lingual surface of the epiglottis in inflammatory conditions of the larynx.Mucosa of the larynx there are 5 layers of the vocal cord under the microscope：Stratified squamous epithelium ，Reink layer，elastic fibre layer，Collagen fiber layer and muscle layer 。Space of the larynxParaglottic SpaceMedially,the space is bounded by the quadrangular membrane,the ventricle and the conus elasricus.Laterally,it is bounded by the perichondrium of the thyroid lamina and the cricothyroid membrane.Anterosuperiorly,the space opens in the posterior portion of the preepiglottic space.It is important in considering the spread of laryngeal cancer.Reink space Is the potential minute gap located between the Vocal cords epithelia and vocal ligament, accounting for the whole length of the vocal cords. This layer is loose connective tissue, and inflammation is formed in the layer .Vocal cord polyps formed in this gap. Space of the larynxSpace of the larynxSuperiorly,it is bounded by the hyoepiglottic ligament and mucosa of the vallecula andInferiorly,by the thyroepiglottic ligament.Anteriorly,thyrohyoid membrane and the inner surface of the thyroid laminaLaterally,the preepiglottic space opens in the paraglottic space.Cancer on the infrahyoid portion of the epoglorris can penetrate this structure and gain access to the preepiglottic spaceBlood Supply & Lymphatics Blood Supply: - Superior thyroid artery Ext. Carotid - Inferior Thyrocervical trunk SubclavianLymphatics: - Glottis No lymphatics - Supraglottic Pre-epiglottic & UDC - Subglottic Pre-laryngeal & pre-tracheal to the LDCNever of the LarynxSuperior Laryngeal: Sensory above vocal folds, motor to Cricothyroid muscleInferior (Recurrent) Laryngeal: Sensory below folds, motor to all muscles except cricothyroidPhysiology of the LarynxProtection of the lower respiratory passages: (The primitive, embryonic & most imp.) 1- Sphicteric Mechanisms (epiglottic-aryepiglottic, V.B. and V.F.) 2- Elevation of the larynx during swallowing 3- Cessation of respiration during swallowing 4- Cough reflex PhonationRespirationFixation of the chestVocal cords polypsOne third of the vocal cords translucent,smoothEtiology1.Improper voice2.Excessive voice3.InfectionSymptomsHoarsenessDyspneaExaminationOne third of the vocal cords translucent,smooth neoplasmMove up and down with the breathTreatmentOperationacute epiglottitisIntroductionAcute epiglottic is a life-threatening infection of the supraglottic larynx most often caused by Haemophilus influedzae type B.It is a true medical emergency.Children aged 2 to 4 years are the most frequently affected group,and cases are more frequent in the winter and spring.Normal Epiglottic EtiologyInfection:Haemophilus influedzae type BInflammationForeign bodySymptonsThe illness begins rapidly over 2 to 6 hours with the onset of fever,sore throat,and inspiratory stridor.The voice tends to be muffled,and the patient has no barkycough,as in croup.As the supraglottic strctures become more edematous,airway obstruction develops.ExaminationSign of the edematous epiglottis with a dilated hypopharynx.TreatmentTreatment is directed at airway maintenance and then toward providing antimicrobial and suppotive care, Drawing blood,starting intravenous lines,obtaining a rectal temperature,or otherwise disturbing the patient should be postponed until the airway is secured.Anatomy and Function of Pharynx and LarynxAnatomyCommon chamber of the respiratory and digestive tracts. Endodermal primitive foregut.12- to 14-cm musculomembranous tube.Base of the skull, back of the nose and mouth, to the level of the sixth cervical vertebra (becomes continuous with the esophagus). Upper part: pseudostratified ciliated epithelium.Lower part: stratified squamous epithelium.AnatomyThe principal muscles of the pharynx:1.superior, middle, and inferior constrictor muscles. 2.posterior midline: pharyngeal raphe.Quadrilateral superior pharyngeal constrictor musclesOrigin: caudal medial pterygoid process, the pterygomandibular raphe, the posterior part of the mandibular mylohyoid line, and the side of the base of the tongue.Pterygopharyngeal, buccopharyngeal, mylopharyngeal, and glossopharyngeal muscle.Pharyngeal recess (Rosenmllers fossa): above the muscles concave upper border, adjacent to the medial part of the eustachian tubes orifice in the nasopharynx.Middle constrictor musclesFan-shapedOrigin: cornua of the hyoid bone and the lower part of the stylohyoid ligament.Inferior constrictor musclesOrigin: lateral surfaces of the thyroid and cricoid cartilages and tendinous arch between both cartilages. Thyropharyngeus muscle: fibers from the thyroid cartilage to the posterior pharyngeal wall.Cricopharyngeus muscle: fibers from the cricoid cartilage to the pharyngeal wall (demarcates the pharynx from the cervical esophagus). Longitudinal musclesPalatopharyngeus muscle: from the anteroinferior surface of the palate to the posterolateral oropharyngeal wall.Salpingopharyngeus muscle: from the nasopharyngeal orifice of the eustachian tube to blend with the palatopharyngeal muscles in the lateral pharyngeal wall.Stylopharyngeus muscle: from the medial base of the styloid process to the posterolateral pharyngeal wall (between the superior and middle constrictor muscles). AnatomyBuccopharyngeal fascia is the deep epimysial covering of the pharyngeal muscles. Retropharyngeal space (between buccopharyngeal fascia and prevertebral fascia).Parapharyngeal space: superiorly to the base of the skull and inferiorly at the level of the hyoid bone (submandibular glands sheath and fascial attachments to the stylohyoid and posterior digastric muscles). Parapharyngeal space is crossed by the styloglossus and pharyngeus muscles (connective tissue above and below these muscles is continuous with the retropharyngeal connective tissue and the retropharyngeal space). AnatomyArteries (ECA): 1) ascending pharyngeal artery, 2) dorsal branches from the lingual artery, 3) tonsillar branches of the facial artery, 4) palatine branches from the maxillary artery. Veins: 1.superiorly pterygoid plexus of veins (and the vertebral plexus).2.inferiorly internal jugular vein. Nerve: 1.stylopharyngeus muscle: glossopharyngeal nerve.2.other pharyngeal muscles: vagus nerve through the pharyngeal plexus. Lymphatic drainageNasopharynx: retropharyngeal lymph nodes lateral pharyngeal and deep jugular nodal chains. Oropharynx: retropharyngeal nodes and the superior deep cervical and jugular nodes. Hypopharynx: retropharyngeal, lateral pharyngeal, deep cervical, and jugular nodes.Pharyngeal AnatomyPosterior and lateral walls are composed of three constrictor, attached to cervical vertibrae posterior.Passavant ridge: when swallowing, soft palate are elevated, forming a fold to seal nasopharyngealConstrictorSuperior constrictor is suspended from the skull base and lateral tongueAnterior attachments of middle constrictor are hyoid and stylohyoid ligament.The inferior constrictor attaches to the thyroid and cricoid cartilagesNo evidence to support that three constrictors contribute to stability of airway.Negative pressure generated with inspiration is maintained by dilation of the lumen by pulling the tongue base or hyoid bone anteriorly.They are genioglossus, geniohyoid, and anterior belly of the digastric muscle. (Pharyngeal dilating muscles)Pharyngeal Airway PhysiologyAirway collapse during sleep in all human and obstructive sleep apnea (OSA) is common. OSA is extreme rara in any other animal.Obstructive Sleep Apnea (OSA)The instability seems to be a result of inferior displacement of the larynx during developmentPharyngeal dilating muscles are active higher levels during wakefulness with OSAMueller ManeuverHighly predictive of OSAGeneration of negative pressure in the pharynxCross-sectional area decreases significantly in OSASnoringCollapsing pressure upstream pressureCollapsing pressure 50% lymphocytes in a total leukocyte population of more than 5,000/mm3. 2.prominent atypical lymphocytes (10% of the total leukocyte count). 3.mild to moderate elevations of liver enzymes. 4.serum heterophile antibodies (positive Mono-Spot test). 5.children 10 years often will not have a positive heterophile antibody test. EBV infectionIgM - VCA disappear within 2 to 3 months after infection.Antibodies to EA disappear within 2 to 6 months after infection.IgG - VCA and anti-EBNA antibodies persist for life and indicate a chronic carrier state.Streptococcal Infection Group A beta-hemolytic Streptococcus (especially in children).Group C and G: severe pharyngitis, reactive arthritis.Incubation period (12 hours to 4 days). Sore throat, difficulty with swallowing, and fever. Affected tissues are inflamed, and there is commonly an exudate. Cervical lymphadenopathy: 60% of patients.Streptococcal InfectionPeak incidence (5-15 years).Less common in infants:1.maternal IgG.2.lack of pharyngeal receptor for streptococcal binding.Diagnosis: swab culture.Treatment: oral or intravenous penicillins, erythromycin, cephalosporins.Complications: rheumatic fever, rheumatic heart disease, acute poststreptococcal glomerulonephritis.Staphylococcal Infection S. aureus (or S. salivarius) Mucopurulent drainage.Mucosal erythema and edema.Localized pustules, especially in the tonsils. Penicillin, erythromycin, or cephalosporin (based on culture and sensitivity results). Diphtheroid Infection Children 10 years.Nose and mouth mucosal surfaces of the upper respiratory tract. Incubation period (2 to 4 days) exotoxins localized tissue necrosis and inflammation gray-black membrane firmly adherent to the underlying tissue.Extension of the membrane to the nasopharynx or the larynx and hypopharynx inability to clear secretions, respiratory obstruction. Diphtheroid InfectionToxin may enter the blood stream and lymphatics, especially if the pharynx and tonsils are infected. Antitoxin remains the only specific method of treatment. Antibiotics (penicillin, erythromycin) are useful as adjuvant therapy in infected patients and in asymptomatic carriers. Fungal Infections Candida albicans. Immune compromised.Pain or dysphagia. Cheesy or creamy mucosal plaques.Treatment: 1.topical nystatin or oral ketoconazole or fluconazole. 2.systemic involvement, amphotericin B may be necessary.Radiation PharyngitisOral and pharyngeal mucosa:1.Very high cell turnover rate.2.Atrophic changes due to inhibition of cellular division by R/T (16-22 cGy).Prevention is impossible.Saliva is reduced bacterial or fungal infection.Oral concoctions: sucralfate, diphenhydramine, antibacterial agents, topical steroids.Pilocarpine: increase salivary flow.Reflux PharyngitisGERD.Often complain of excessive phlegm rather than heartburn.Hoarseness, sore throat, chronic cough, globus pharyngeus, halitosis, dysphagia.Most reliable sign: arytenoid erythema.Mild pharyngeal erythema, posterior pharyngeal cobblestoning.PFAPAPeriod fever (up to 40.5), aphthous stomatitis, pharyngitis, cervical adenitis.Children around the age of 3 years.5-days episodes/ every 28 days and asymptomatic betwwen episodes.No long term sequelae.Glucocorticoid effectively control symptoms.Tonsillectomy and cimetidine may lead to remission.LaryngitisDefinitionLarynx has some inflammatory process ofAcute or chronicLocalized or systemicInfectious or noninfectiousMisused as hoarsenessClinical PresentationsDepends on its causeThe amount of edemaRegion involvedAgeDiagnosisHistoryGradual or suddenStridorURIHeartburnDuration, chronicityIntermittent or progressiveExaminationListen to voice, breathingLaryngoscopy, indirect or fibroscopeX-rays studiesSkin testLab testbiopsyAdult Laryngitis1.Infectious2.Systemic disease3.ReactiveInfectious LaryngitisViral commonly rhinovirus, parainfluenza, rare CMV, HPV, HSVBacterial H. influenzae, streptococcus, staphylococcus, KlebsiellaFungal - candida, aspergillus, coccidiomycosis, blastomycosisMycobacteriumProtozoan rare lesishmaniasis cryptosporidiosisSystemic diseases causing laryngitisWegener granulomatosisRheumatoid arthritisAmyloidosisRelapsing polychondritisSLESarcoidosisEpidermolysis bullosaCicatricial pemphigoidReactive laryngitisLaryngopharyngeal refluxSmokingVoice abuseInhaled steroidsInhaled exposure Freon, formaldehyde, solventsAngioedemaAllergyViral laryngitisMost commonly associated with a viral URIRhinovirus is the most common agentS/S: dysphonia, voice breaks, episodic aphonia, lowered vocal pitch, cough, throat painVocal fold mucosa is erythematous and edematousSelf-limited. Treated by humidification, voice rest, hydration, smoking cessation, cough suppresants, and expectorants.Antibiotics are preserved for secondary bacterial infectionBacterial LaryngitisAcute epiglottitis: H. influenzae, S. pneumoniae, S. aureus, K. pneumoniaeEpiglottic abscess: uncommon complication of supraglottitis. Most in adults than childrenFungal LaryngitisMost is immunocompetentMost is candidaLeukoplakia and as pseudoepitheliomatosis hyperplasiaHistoplasmosisSystemic mycotic disease by Histoplasma capsulatumSuperficial granulomas, ulcerous, painfulTreated by Amphotericin BBlastomycosisSmall, red, granular lesion of the laryngeal mucosa, progress to painful abscess and ulcerationTreatment is with long-term Amphotericin B, ketoconazole, or itraconazoleTuberculosisThe most common granulomatous disease of larynxOften associated with active pulmonary tuberculosisDiffusely edematousPosterior third of larynx or granular exophytic lesion, resemble carcinomaLeft untreated, stenosis may developSyphilisLater stageLesion mimic carcinoma along with cervical LAP during 2nd stageSpontaneously clear within weeksGumma formation during 3rd stage, leading to fibrosis, chondritis, and stenosisLeprosyRare in US, but common in Africa and IndiaMost involved in supraglottisMuffled voice, odynophagia, and coughNodules with ulcerScleromaCaused by Klebsiella rhinoscleromatisPrimarily involved in nasal cavity, and may extend to laryngopharynx.3 overlapping stages1.Catarrhal stage, purulent rhinorrhea, nasal crusting and obstruction2.Granulomatous stage, nodular granuloma in upper respiratory tract, subglottis is the most involved3.Sclerotic stage, fibrosis and scar formationImmunocompromised HostAIDS, developing opportunistic infection and malignancies, including Kaposi sarcoma, non-Hodgkin lymphoma, squamous cell carcinomaSystemic Inflammatory Disease Causing LaryngitisSLE1/3 cases produce laryngeal inflammationFrom intermittent dysphonia to airway obstructionThe most common is dysphonia and dyspneaWegener GranulomatosisNecrotizing granuloma with vasculitis involving the respiratory tract and kidneyNasal involvement (90%), laryngeal involvement (25%)Initially resemble acute laryngitis, progress to ulcerous granuloma in larynxTreatment of subglottic involvement includes mechanical dilation, intratracheal injection of steroid, topical use of mitomycin, eventually laryngotracheoplastyAmyloidosisProtein deposition in extracellular space, peak age at 50Two types, primary type associated with immunocyte dyscrasia like multiple myelomaSecondary type as chronic inflammation like RA, IBS, TBDifficult D.D.Usually asymptomatic until deposit involves vocal cordRelapsing PolychondritisEpisodes of inflammation and fibrosis with destruction the cartilage of ear, nose, larynx, and tracheaLarynx involved more than 50%, manifested by dysphonia, dysphagia, and throat painThe etiology is unknown, but pathology seemed to immunoreaction to type II collagenRheumatoid Arthritis25% of case reported laryngeal involvementGlogus, hoarseness, stridor, and dysphagia2 stages: active phase is tender and erythematous, chronic phase, mucosa is normal but cricoarytenoid joint is ankylosed, submucosal nodules on vocal foldSarcoidosisMultisystem granulomatous disease of unknown etiologyDiagnosis based on noncaseating granulomas and pale diffuse edema of supraglottis and excluding tuberculosis, Wegener, and fungal disease.Treatment by endoscopic surgery, low-dose radiation, and inhaled steroidEpidermolysis Bullosa and Cicatricial PemphigoidCutaneous symptomsMucosal blister formationRare laryngeal involvementIntubation should be avoided because of larynx is sensitive to trauma.Tracheostomy is favoredInflammatory LaryngitisThermal injuryDysphonia reportedCommon in exposure to steam, smoke, or hot liquid or food (especially microwaved)Supraglottic edema and erythemaMore common in childrenFreebase cocaine present in similar wayTreatment by humidification, steroid, OBS, or intubationLaryngopharyngeal Reflux (LPR)Except infectious laryngitis, LPR is the most common noninfectious laryngitis.LPR implicated by vocal cord granulomas, laryngeal stenosis, recurrent laryngospasm, globus pharyngeus, cervical dysphagia, asthma, laryngeal carcinoma, chronic cough, subglottic stenosis.Laryngopharyngeal Reflux- ExaminationPosterior laryngitis by red arytenoid with interarytenoid mucosa hypertrophyInfraglottic edema is frequentlyDiffuse laryngeal edema, Reinkes edema, mucosal thickening without significant erythema, so that ventricular effacementDiffuse erythema with granular, friable mucosa, vocal process granulomaDiagnosis of LPRGold standard is ambulatory 24-hour double-probe pH monitoringDistal probe is placed 5cm above the lower esophageal sphincter and proximal probe is above upper esophageal sphincterTreatment - LPRDietary and lifestyle modifications, like avoidance of fatty meals, caffeine, alcohol, smoking, oral intake within 2 hrs of lying down.Head of bed elevation is indicatedAntireflux medication, like PPI, H2 blockers23 months of treatment, significant improvementTraumatic LaryngitisCommonly by vocal abuseAngioedemaInflammatory reaction, caused by bradykinin. Not IgE mediated allergic reaction.Etiologic agents include medications, especially ACEI, food, insect bites, transfusion, and infections.Treatment - AngioedemaMust aggressive, maybe intubation or tracheostomy Oxygen, epinephrine, steroid, antihistamines, and aminophyllineACEI type is refractory to treatmentAllergic LaryngitisThe most common trigger is insecticides, phenol, petroleum-based compounds, formaldehyde, and other allergensSkin test or RASTRadiation LaryngitisTreatment by hydration, humidification, acid suppression with steroidSometimes antibioticsInhaled SteroidsOne half of patients taking inhaled corticosteroids notice some laryngeal symptoms.Mechanism is unclear: antiinflammatory steroid causes inflammationSubstance and turbulent flow may play a role.Symptoms very between odynophagia, dysphonia, dysphagia, and globusImmunologic Defenses of Laryngeal MucosaHistorically, no immune functionA strong barrier of innate and acquired immunity Acute EpiglottitisAnatomy of EpiglottisA thin lamina of elastic cartilage covered on all sides with mucous membraneLeaf-shaped, the stalk (petiole) attachement to larynx via thyroepiglottic ligament.Back wall of the vallecular space Histology of EpiglottisInvested by a mucous membrane that is continuous with the mucosa of tongue base and lateral pharyngeal walls.Covered anteriorly by a stratified squamous epithelial layer. This squamous layer also covers the superior third of the posterior surface, where it merges with respiratory epithelium that extends into the larynx. Functions of EpiglottisUpwards and backwards over the vestibule like a “lid”However, it does not seem to function as such. If surgical removal, has no adverse effectsBackgroundEpiglottitis, also called supraglottitis, is a rapidly progressive infection of the epiglottis and adjacent tissues usually caused by bacteria.The local inflammation and edema lead to airway obstruction that can result in death without emergent intervention.Epidemiology2 to 7 years oldHaemophilus influenzae type B most commonIncidence greatly decreased since vaccineEtiology (1)Infectious causes H. influenzae type A and nontypable strains H. parainfluenzaeStreptococcus pneumoniaeStaphylococcus aureusBeta-hemolytic streptococciEtiology (2)Noninfectious causes thermal injurycorrosive ingestionposttransplant lymphoproliferative diseasepreparative therapy for bone-marrow transplantationgraft-versus-host diseaseMechanism (1)Epiglottitis is generally a cellulitis of the epiglottis, aryepiglottic folds, and other adjacent tissues.The squamous epithelial layer is loosely adherent to the cartilage, creating a large potential space that can expand as inflammatory cells and edema fluid accumulate during infection.Mechanism (2)As this potential space expands with edema, the epiglottis curls posteriorly and inferiorly over the laryngeal inlet.It then acts as a ball-valve, obstructing airflow during inspiration but permitting free expiration. This can lead to hypoxemia with hypercapniaPathogenesisThe primary source of Hib microbes that invade the epiglottis is probably the posterior nasopharynx.It is possible that microscopic trauma to the epithelial surface from food during swallowing or mucosal damage from a viral infection could be predisposing factors.It is unclear whether some hosts are genetically more susceptibleClinical PresentationMany have minor antecedent URI symptoms, the usual duration of notable illness prior to hospitalization is less than 24 hours and frequently less than 12 hours.Sudden onset of the constellation of fever, severe sore throat, dysphagia, and drooling is common. SymptomsFever between 38.8 and 40.0CAirway obstruction Choking sensation, is distressed on inspirationAnxious, restless, and irritableHoarseness, as seen in laryngitis, is uncommon.Sitting with arms back, trunk leaning forward, neck hyperextended, and chin thrust forward SignsDysphagia leading to droolingMuffled or hot potato voiceVoice change, including cryStridor is not commonLeukocytosisClinical DiagnosisClinical presentation and then confirmed by visualization of the epiglottisCultures of blood or the surface of the epiglottis confirm the microbial pathogenX-ray is not necessaryImaging StudiesLateral neck radiographs also have been a mainstay in the diagnosis of epiglottitis. Radiographs is of an enlarged epiglottis protruding from the anterior wall of the hypopharynx (the thumb sign) The hypopharynx may appear dilated and the cervical spine is straightened instead of the usual mild lordosis.Differential DiagnosisLaryngotracheitis (croup) or spasmodic croup (angioedema-like response with less inflammation visible by laryngoscopy) Bacterial tracheitis Uvulitis Foreign body lodged in the larynx or vallecula Peritonsillar or retropharyngeal abscesses Angioedema Congenital anomalies of the upper airway Laryngotracheobronchitis croup - Scottish for barking cough6 months to 3 years oldParainfluenza viruses types 1 and 2 most commonLaryngotracheobronchitisURI symptomsbarking coughhoarsenessinspiratory stridorlow-grade feverLaryngotracheobronchitislaryngoscopy for those with respiratory distressAP neck - “steeple sign”supraglottis normalLaryngotracheobronchitisusually self-limitedhumidified airracemic epinephrinesteroidshelioxintubation for severe, refractory casesSpasmodic Crouppresentation similar to LTBsudden onset stridorafebrilerecurrent episodes that resolve spontaneouslyunknown causeBacterial Tracheitis“steeple sign” on AP neckintraluminal soft tissue irregularitiesendoscopy best diagnostic methodBacterial Tracheitissubglottic edemaulcerationpseudomembrane formationsuction and debridenasotracheal intubationIV antibioticsextubate after 3-7 daysAdult EpiglottitisDifferent infectious organisms.Larynx and oropharynx are inflamed but epiglottis may be spare.TreatmentEndotracheal tubeAntibiotics: Unasyn, Cefuroxime, Rocephin, aztreonam, chlormphi