From the Guidelines
An irritative cough is a persistent cough triggered by irritation or inflammation in the airways rather than by an infection or underlying disease, and it is essential to identify and address the underlying cause to alleviate symptoms and improve quality of life. This type of cough typically occurs when nerve receptors in the respiratory tract are stimulated by irritants such as dust, smoke, pollution, post-nasal drip, acid reflux, or dry air 1. For immediate relief, try drinking warm fluids like tea with honey, using a humidifier to add moisture to the air, and avoiding known irritants. Over-the-counter options include cough suppressants containing dextromethorphan (such as Robitussin DM, 10-20 mg every 4 hours for adults) or throat lozenges with menthol. For acid reflux-related coughs, antacids or H2 blockers like famotidine may help 1. If the cough persists beyond 2-3 weeks, worsens, or is accompanied by symptoms like fever, chest pain, or difficulty breathing, medical evaluation is necessary as it could indicate a more serious condition 1. The irritative cough mechanism involves hypersensitivity of cough receptors, which can develop a lower threshold for activation, making them more responsive to even mild irritants. Some key points to consider in managing irritative cough include:
- Identifying and addressing the underlying cause of the cough
- Using empiric treatment approaches, such as directing treatment at the most common causes of cough (e.g., UACS, asthma, NAEB, and GERD) 1
- Considering sequential and additive treatment steps, as more than one cause of cough may be present 1
- Counseling and assisting patients with smoking cessation, as smoking can exacerbate cough symptoms 1
- Stopping and replacing ACE inhibitors, which can cause cough as a side effect 1.
From the Research
Definition of Irritative Cough
- An irritative cough is a type of cough that occurs in response to the presence of irritants in the respiratory tract 2.
- Irritants can be non-corrosive chemicals that cause reversible inflammatory changes on living tissue by chemical action at the site of contact 2.
Causes of Irritative Cough
- Occupational and environmental irritants can play a role in the pathogenesis of chronic cough, including irritative cough 2.
- The clinical and pathologic spectrum of chemically induced respiratory tract irritation can range from neurogenically mediated alterations in regional blood flow, mucus secretion, and airway caliber to the initiation of cough 2.
Mechanism of Irritative Cough
- The chemosensory type of cough reflex can be activated or hyperactivated after lung injury, with lung inflammation, or in response to chemicals, including irritants 2.
- Normally quiescent transient receptor potential (TRP) cation channels TRPV1 (vanilloid) and TRPA1 (ankyrin) can become activated or hyperactivated in response to irritants, leading to the initiation of cough 2.
Relationship to Dry Cough
- An increased sensitivity of the cough reflex can be observed in patients with dry cough, which can be similar to irritative cough 3.
- Antitussive preparations, including codeine or dextromethorphan with antihistamines, decongestants, and expectorants, can be used for symptomatic relief of dry or non-productive cough, including irritative cough 3.