Some Causes of Wheezing
Cause | Suggestive Findings | Diagnostic Approach* |
|---|---|---|
URI symptoms No known history of lung disease | History and physical examination | |
Allergic reaction | Sudden onset, usually within 30 minutes of exposure to known or potential allergen Often nasal congestion, urticaria, itchy eyes, sneezing | History and physical examination Allergy testing (skin or blood) Measurement of serum eosinophils |
Often known history of asthma Wheezing arising spontaneously or after exposure to specific stimuli (eg, allergen, URI, cold, exercise) | History and physical examination Pulmonary function testing† Sometimes, peak flow measurement or observation of response to empiric bronchodilators Rarely, methacholine challenge | |
In children < 18 months (usually from November to April in the Northern Hemisphere) Usually URI symptoms and tachypnea | History and physical examination Sometimes rapid antigen tests or molecular tests like RT-PCR | |
COPD exacerbation | In middle-aged or older patients Often known history of COPD Extensive smoking history Poor breath sounds Dyspnea Pursed lip breathing Use of accessory muscles | History and physical examination Sometimes chest radiograph and ABG measurement |
Medications (eg, ACE inhibitors, aspirin, beta-blockers, NSAIDs) | Usually, recent initiation of a new medication, most often in a patient with a history of reactive airway disease | History and physical examination |
Endobronchial tumors | Fixed and constant inspiratory and expiratory wheezes, especially in a patient with risk factors for or signs of cancer (eg, smoking history, night sweats, weight loss, hemoptysis) May be focal rather than diffuse | Chest radiograph or CT Bronchoscopy (usually preceded by pulmonary function tests with flow-volume loops that indicate obstruction) |
Foreign body | Sudden onset in a young child who has no URI or constitutional symptoms | Chest radiograph or CT Bronchoscopy |
GERD with chronic aspiration | Chronic or recurrent wheezing, often with heartburn and nocturnal cough Absence of URI, asthma, COPD, or allergic symptoms | Trial of gastric acid-suppressing medications Sometimes esophageal pH monitoring |
Sudden onset after occupational exposure or inappropriate use of cleaning agents | History and physical examination | |
Left-sided heart failure with pulmonary edema (cardiac asthma) | Crackles and signs of central or peripheral volume overload (eg, distended neck veins, peripheral edema) Orthopnea or paroxysmal nocturnal dyspnea | Chest radiograph ECG BNP measurement Echocardiography |
* Most patients should have pulse oximetry. Unless symptoms are very mild or are clearly an exacerbation of a known chronic disease, chest radiography should be done. | ||
ABG = arterial blood gas; ACE = angiotensin-converting enzyme; BNP = brain (B type) natriuretic peptide; COPD = chronic obstructive pulmonary disease; CT = computed tomography; ECG = electrocardiogram; GERD = gastroesophageal reflux disease; NSAID = nonsteroidal anti-inflammatory drug; RT-PCR = reverse transcriptase-polymerase chain reaction; URI = upper respiratory infection. | ||