<prompt> A 28 year old man presents with cough, shortness of breath wheezing. The symptoms started when he was running initially. Now the symptoms are present while walking or even at rest. During childhood he suffered from atopic dermatitis. His father and sister also suffered from atopic dermatitis. He also has hay fever from 14 years of age. The cause of bronchospasmCOPDSmokingType 1 hypersensitivityExercise  <response>: Answer: c Type I hypersensitivity HARRISON 19TH ED, P-1669; ROBBINS 9TH ED, P-679ASTHMAHall marks of the diseaseIncreased airway responsivenessEpisodic bronchoconstrictionInflammation and hyperplasia of the bronchial wallsIncreased mucous secretion Atopic asthmaMost common typeClassic example of IgE-mediated type I hypersensitivity reactionUsually begins in childhoodPositive family history and skin test positiveCommonly suffer from other atopic diseases, particularly allergic rhinitis, which may be found in over 80 of asthmatic patients, and atopic dermatitis eczemaExaggerated TH2 and IgE response to environmental allergens dusts, pollen, animal dander, animal foods in genetically predisposed individualsThe TH2 cytokines IL-4, IL-5, and IL13 are important mediatorsDiagnosed by allergen sensitization by serum radio-allergosorbent tests RASTNon-Atopic asthmaNo evidence of allergen sensitization; No family history; Negative skin testsTriggered by viral respiratory infectionsRhinovirus, parainfluenza and RSV are the most common organismsnot bacteriaDrug induced asthmaAspirin sensitive asthma in patients with recurrent rhinitis and nasal polypsExercise-induced bronchoconstriction:Begins during exercise or within 3 minutes after its end.Peaks within 10-15 minutes.Resolves by 60 minutes.This phenomenon is thought to be a consequence of the airways attempt to warm and humidify an increased volume of expired air during exercise.Cardiac asthma - wheezing precipitated by decompensated heart failure.Catamenial asthma - Women may experience at predictable times during the menstrual cycle.MorphologyThe most striking finding - occlusion of bronchi bronchioles by thick, tenacious mucous plugsHistologically the mucous plugs contains whorls of shed epithelium Curschmann spiralsSputum contains Charcot-Leyden crystalsEpithelial cells present in the sputum - Creola bodies Clinical featuresWheezing, breathlessness, chest tightness and cough particularly at night or early morningSeverity of asthma exacerbationsFeatureMildModerateSevereImminent respiratory arrestBreathlessnessWhile walkingAt rest, limits activityAt rest, interferes with conversationAt rest, muteTalks inSentencesPhrasesWordsSilentRespiratory rateIncreasedIncreased 30min 30minUse of accessory muscles; suprasternal retractionsAbsentCommonlyUsuallyParadoxical thoracoabdominal MovementWheezeEnd expiratoryThroughout expirationThroughout inspiration and expirationAbsentPulsemin100100 -120120BradycardiaPulsus paradoxusAbsent 10 mm HgMay be present 10- 25 mm HgOften present 25 mm HgAbsence suggests respiratory muscle fatiguePEF or FEV1 predicted or personal best 7040-6940 25PaO2 on air, mm HgNormal606060PCO2 mm Hg 42 mm Hg42 mm Hg42 mm Hg42 mm HgSaO2 on air9590-95 90 901 kPa 7.5 mmHgClassification of asthma severityFeatureIntermittentPersistentMildModerateSevereSymptoms 2 daysweek 2 daysweekDailyThroughout dayNight awakenings 2month3 - 4month 1week but not dailyDailyShort-acting B2-agonist use for symptom control 2 daysweek 2 daysweek, but not dailyDailySeveral times per dayInterference with normal activityNoneMinor limitationSome limitationExtreme limitationFEV1Normal between Exacerbations 80 predicted 80 predicted60 - 80 60FEV1 FVCNormalNormal5 reduced 5 reducedLife-threatening acute severe asthma - featuresPEF 33 predicted 100 LminSpO2 92 or PaO2 60 mmHgNormal or raised PaCO2Silent chestCyanosisFeeble respiratory effortBradycardia or arrhythmiasHypotensionExhaustionConfusionComaDiagnosis of asthma: Compatible clinical history any one of the following15 and 200 mLincrease in FEV1 following administration of bronchodilator or corticosteroids Positive bronchodilator response - strongly confirms the diagnosis of asthma20 diurnal variation on 3 days in a week for 2 weeks on Peak expiratory flow PEF meter diaryFEV1 15 decrease after 6 minutes of exercise Note:Bronchial provocation testing with inhaled histamine or methacholine may be useful when asthma is suspected but spirometry is non-diagnostic.Bronchial provocation is not recommended if the FEV1 is less than 65 of predicted.A positive methacholine test is defined as a 20 fall in the FEV1 at exposure to a concentration of 8 mgmL or less.A negative test has a negative predictive value for asthma of 95.Asthma managementSeveritySymptoms and SignsInitial PEF or FEY1Clinical CourseMildDyspnea only with activityPEF 70 predicted or personal best Usually cared for at home Prompt relief with inhaled SABA Possible short course of oral systemic corticosteroidsModerateDyspnea interferes with or limits usual activityPEF 40-69 predicted or personal best Usually requires office or ED visit Relief from frequent inhaled SABA Oral systemic corticosteroids; some symptoms last for 1-2 days after treatment is begunSevereDyspnea at rest; interferes with conversationPEF 40 predicted or personal best Usually requires ED visit and likely hospitalization Partial relief from frequent inhaled SABA Oral systemic corticosteroids; some symptoms last for 3 days after treatment is begun Adjunctive therapies are helpfulSubset: Life- threateningToo dyspneic to speak; perspiringPEF 25 predicted or personal best Requires EDhospitalization; possible ICU Minimal or no relief from frequent inhaled SABA Intravenous corticosteroids Adjunctive therapies are helpfulED, emergency department; FEV1, forced expiratory volume in 1 second; ICU, intensive care unit; PEF; peak expiratory flow; SABA, short acting b2-agonist.Oral corticosteroids should generally be prescribed for early administration at home in patients with moderate to severe asthmaExcept for the respiratory rate of 35min, the patient given in the question has moderate asthma pulse rate- 120min, BP-11070 mmHg, Oxygen saturation of 90 most important and peak expiratory flow less than 50STEP WISE MANAGEMENT OF BRONCHIAL ASTHMAStep 1Step 2Step 3Step 4Step 5MildintermittentMildpersistentModerate persistentSevere persistentVery severe persistentSABA when neededRegular SABA low dose ICS200ugAdd LABA Benefit present, but inadequate control- continue LABA ICS dose 800mg No response: stop LABA ICS dose 800mgday ICS dose upto 2000mgday Addition of fourth drug: leukotriene receptor antagonist, SR theophylline, b2- agonist tablet Use daily steroid tablet High dose ICS 2000ugday Refer for specialist careICS -inhaled corticosteroid; LABA - inhaled long acting beta-2-agonist; LTRA-leukotriene receptor antagonist; SABA - inhaled short acting beta-2-agonist; OCS - oral corticosteroidsNAEPP 3 recommendations emphasize daily anti-inflammatory therapy with inhaled corticosteroids as the cornerstone of treatment of persistent asthma. 