WBR0090

Author	PageAuthor::Sapan Patel M.B.B.S.
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Community Medical Health Center, MainCategory::Primary Care Office
Sub Category	SubCategory::Allergy/Immunology, SubCategory::Respiratory
Prompt	[[Prompt::A 19-year-old male presents for evaluation of shortness of breath. He has episodes of wheezing sound and chest tightness. His symptoms worsen if he tries to exercise, especially when it is cold. He has used an over the counter inhaler with good relief of his symptoms, but he finds that his symptoms are worsening. He now has episodes of wheezing on a daily basis and will have nighttime wheezing and coughing, on average, four or five times a month. Physician suspects a diagnosis of asthma. Which of the following would confirm his suspicion of the diagnosis of asthma?]]
Answer A	AnswerA::Presence of expiratory wheezing on examination
Answer A Explanation	AnswerAExp::Incorrect- Expiratory wheezing on examination is commonly seen in asthma but is a nonspecific finding.
Answer B	AnswerB::Increase in FEV1 of 15% after giving inhaled albuterol
Answer B Explanation	[[AnswerBExp::Correct- Airflow obstruction can be shown by spirometry revealing an FEV1 of <80% predicted or an FEV1/FVC(forced vital capacity) of <65% of the lower limit of normal. Reversibility can be shown by an FEV1 increase of 15% and at least 200 mL with the use of a short-acting beta agonist like inhaled albuterol.]]
Answer C	AnswerC::A decreased serum IgE level
Answer C Explanation	AnswerCExp::Incorrect- Many patients with asthma have elevated serum IgE levels; it is unusual to find asthma in individuals who have a low level of serum IgE.
Answer D	AnswerD::A peak expiratory flow measurement 30% below the predicted normal value for the patient
Answer D Explanation	AnswerDExp::Incorrect- Peak-flow monitoring is useful for the short- and long-term monitoring of asthma patients and for exacerbation management but not for primary diagnosis.
Answer E	AnswerE::Presence of eosinophils on a sputum sample
Answer E Explanation	[[AnswerEExp::Incorrect- The sputum of asthmatics may contain eosinophils, Charcot-Leyden crystals, Curschmann spirals, or Creola bodies. However, eosinophils may also be present in the sputum of patients with other conditions such as Churg-Strauss syndrome or eosinophilic pneumonia.]]
Right Answer	RightAnswer::B
Explanation	[[Explanation::Asthma is a chronic lung disease characterized by inflammation of the airways, causing recurrent symptoms. The characteristic symptoms are wheezing, chest tightness, shortness of breath, or cough. Symptoms often worsen in the face of certain triggers, which include allergens, cold air, exercise, or other irritants. Physical examination may reveal hyperexpansion of the thorax, expiratory wheezing with a prolonged expiratory phase of respiration, and signs of allergies or atopic dermatitis. Educational objective: Asthma can be diagnosed by a history of episodic symptoms of airway obstruction (wheeze, dyspnea, cough, chest tightness), establishing the presence of airflow obstruction that is at least partially reversible and ruling out other causes of these symptoms/signs. Educational Objective: References: ]]
Approved	Approved::Yes
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