All wheezing should be evaluated for possible asthma, bronchitis and other causes. 

Wheezing is a very common symptom of diverse group of disorders. It should be evaluated carefully to find the underlying cause and to treat it in a timely fashion.

CAUSES — While asthma and chronic obstructive pulmonary disease are the most common causes of wheezing, a variety of other conditions can produce airflow obstruction and thereby expiratory and/or inspiratory wheezing . Causes of wheezing are generally categorized based on their location in one of the following three anatomic areas:

●The extrathoracic upper airway, which includes the nose, mouth, pharynx, larynx, and extrathoracic trachea

●The intrathoracic central airway, which includes the intrathoracic trachea and bronchi at least 2 mm in diameter

●The intrathoracic lower airways, which include airways narrower than 2 mm in diameter

Extrathoracic upper airway causes of wheeze — Extrathoracic causes of wheeze/stridor are more likely to be associated with a monophonic inspiratory sound (stridor), but are sometimes associated with expiratory stridor.

●Anaphylaxis ─ The abrupt onset of stridor and respiratory compromise, associated with generalized urticaria, pruritus or flushing, swollen lips-tongue-uvula, or hypotension, is a classic manifestation of anaphylaxis triggered by food, insect sting, medication, or radiographic contrast. In the context of anaphylaxis, stridor is caused by laryngeal edema.

●Vocal cord edema or paralysis — Following tracheal extubation, patients may develop vocal cord (also known as vocal fold) edema or paralysis. In patients with bilateral vocal cord paralysis, the vocal cords may be adducted to a median position and cause airflow obstruction that is greater during inspiration than expiration. During expiration, the paralyzed cords open due to the force of airflow during exhalation.

●Paradoxical vocal cord motion — Paradoxical vocal cord motion (PVCM) refers to inappropriate movement of the vocal cords (also called vocal folds), resulting in functional airway obstruction.

●Laryngeal stenosis ─ Laryngeal stenosis can result from irradiation, endotracheal intubation, or laryngeal trauma.

●Laryngocele ─ A laryngocele is an abnormal dilation of the laryngeal saccule, which rises vertically between the false cord, the base of the epiglottis, and the inner surface of the thyroid cartilage.

●Tonsillar hypertrophy ─ The association of tonsillar hypertrophy with wheezing has largely been reported in children and adolescents.

●Goiter ─ A larger goiter can cause compression of the extrathoracic airway.

●Postnasal drip syndrome — Postnasal drip can also cause wheezing

Intrathoracic central airway causes of wheeze — A variety of processes can cause wheezing due to obstruction of the intrathoracic trachea and mainstem bronchi . These processes include the following:

●Tracheal stenosis − Tracheal stenosis can be caused by processes such as scarring from endotracheal intubation, prior tracheostomy, granulomatosis with polyangiitis (Wegener’s), tracheobronchopathia osteochondroplastica, gastroesophageal reflux disease with aspiration, and cicatricial pemphigoid.

●Tracheal and bronchial tumors – tumors, both benign and malignant, can cause wheezing.

●Respiratory papillomatosis − Respiratory papillomatosis, a consequence of neonatal human papillomavirus infection, typically presents in infancy, but may recur in adulthood.

●Tracheomalacia, tracheobronchomalacia, and hyperdynamic airway collapse – Tracheomalacia refers to focal or diffuse loss of structural integrity of the tracheal cartilage rings.

●Relapsing polychondritis – Relapsing polychondritis is an immune-mediated condition associated with inflammation of cartilaginous structures. Involvement of the larynx, trachea, and bronchi can lead to areas of stenosis (eg, subglottic stenosis) or loss of cartilaginous support (tracheobronchomalacia) with dynamic laryngeal collapse during forced inspiration and/or tracheal collapse during expiration.

●Tracheobronchial amyloid − Tracheobronchial amyloid is a rare, localized form of amyloidosis that can cause plaques in the central airways and resultant airflow obstruction.

●Mucus plugs ─ Mucus plugs can cause intermittent airway obstruction in patients with pneumonia, non-cystic fibrosis bronchiectasis, cystic fibrosis, asthma, allergic bronchopulmonary aspergillosis, or bronchocentric granulomatosis.

●Vascular rings and aneurysms − Vascular rings (eg, double aortic arch, right aortic arch with aberrant left subclavian) and aneurysms can cause extrinsic tracheal compression and dyspnea.

●Mediastinal mass ─ Mediastinal masses that cause extrinsic compression of the airway (eg, thymoma, germ cell tumors, lymphoma), lymphadenopathy (eg, sarcoid), or substernal goiter can result in wheezing.

Intrathoracic lower airway causes of wheeze — Wheezing in asthma and COPD is largely due to airway narrowing by mucosal inflammation, bronchial smooth muscle constriction, and intraluminal secretions. Diseases such as reactive airways dysfunction syndrome, infectious bronchitis, and infectious bronchiolitis can also cause diffuse or scattered airflow limitation and wheeze.

●Bronchiectasis due to recurrent infections or parenchymal fibrosis with traction − Wheezing in patients with non-cystic fibrosis bronchiectasis and cystic fibrosis can be caused by secretions in the airways, and thus come and go, or be due to airway collapse from scarring and loss of cartilaginous support.

●Bronchiolitis ─ Adults with acute bronchiolitis due to respiratory syncytial virus infection can present with wheezing, although lower respiratory tract symptoms are less common in adults than children. Patients frequently have concomitant symptoms of fever, coryza, rhinorrhea, and conjunctivitis.

●Bronchiolitis obliterans − Bronchiolitis obliterans may develop as a result of viral infection, rheumatic disease, toxic exposures, or graft-versus-host-disease (eg, post lung transplant or hematopoietic cell transplant). Wheezes and/or end-inspiratory squeaks may be heard.

●Cardiac asthma − Episodic wheezing and dyspnea are occasionally described in patients with heart failure in the absence of asthma or COPD. It is thought that vascular congestion and perivascular edema within the bronchovascular bundles cause narrowing of the bronchi and thereby wheezing.

●Carcinoid tumors − Carcinoid tumors can cause a focal wheeze via obstruction of the airway or diffuse wheezes due to release of neuropeptides that cause bronchoconstriction as part of the carcinoid syndrome. Carcinoid syndrome due to bronchial carcinoid tumors is rare and usually associated with large tumors (>5 cm).

●Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) – This is a rare disease that occurs most commonly in nonsmoking, middle-aged women.

●Occupational causes of nonasthmatic wheeze − Farmers with silo-filler’s disease due to inhalation of a high concentration of nitrogen dioxide can develop acute lung injury, sometimes associated with wheezing. Wheezing has also been reported in arc welders.

●Parasitic infection ─ Parasitic infections, such as Ascaris, Strongyloides, and/or filaria, in patients who visited or reside in endemic areas can lead to wheezing from visceral larva migrans (eg, Ascaris lumbricoides, hookworms, and Strongyloides stercoralis) or the burden of bloodborne microfilaria. Peripheral blood eosinophilia is common.

●Reactive airways disease syndrome − Reactive airways disease syndrome is considered a form of asthma, in which inhalation of a high concentration of an irritant causes nonimmunologic provocation of prolonged bronchial hyperresponsiveness.

●Airway distortion – Diseases such as sarcoidosis and tuberculosis can cause sufficient lung parenchymal scarring to result in airway distortion and wheezing.

●Focal wheeze − A number of localized lower airway processes can cause focal wheezing, including a foreign body lodged in a bronchus, bronchial tumors, extraluminal compression (eg, lymphadenopathy, bronchogenic cyst), and congenital anomalies (eg, tracheal bronchus).

This information might be overwhelming to a non-medical person, but we just wanted you to know that wheezing could be coming from many different diseases beside asthma. If you have wheezing it should evaluated by a physician. Please visit Dr.Paul’s Clinic for full diagnosis, imaging and treatment plans.