Latest 2018 guideline for Chronic Cough by KAAACI

The Korean Academy of Asthma, Allergy and Clinical Immunology has released practice guidelines for chronic cough (CC) in adults and children in Korea. The guideline published in the journal Allergy, Asthma & Immunology Research aims to address major clinical questions regarding empirical treatment, practical diagnostic tools for non-specific chronic cough, and available therapeutic options for chronic wet cough in children and unexplained CC in adults in Korea.

EMPIRICAL TREATMENT FOR NON-SPECIFIC CHRONIC COUGH

Use of Histamine H1-Receptor Antagonists (H1RAs) for Treatment of Non-Specific Chronic Cough

Recommendation for adults

For adults with non-specific CC, the empirical use of H1RAs is recommended. This recommendation is supported by the low costs, ease of accessibility, and tolerable safety profiles of H1RAs. However, possible side effects must be discussed with patients.

Recommendation for children

For children with non-specific CC, the authors suggest against the empirical use of H1RAs. The use of H1RAs in children with a non-specific cough must be balanced against the well-known adverse events, especially in very young children. Current data suggest that the use of H1RAs would be more efficacious in children with suspected allergic rhinitis.

Use of Inhaled Corticosteroids (ICSs) for Treatment of Non-Specific Chronic Cough

Recommendation for adults

For adults with non-specific CC, the empirical use of ICSs is suggested. Short-term (2-4 weeks), high-dose ICS treatment is recommended as an empirical regimen. The guidelines suggest performing objective tests to diagnose asthma and eosinophilic bronchitis (such as methacholine challenge, induced sputum analyses, or FeNO measurement) prior to initiating empirical treatment where diagnostic tests are available because the documentation of corticosteroid-responsive conditions justifies long-term treatment. Otherwise, only short-term (2–4 weeks) treatment is warranted.

Recommendation for children

For children with non-specific CC, the administration of ICSs for a well-defined period is suggested. The use of high-dose ICSs in children with non-specific chronic cough must be balanced against well-known potential adverse events. A therapeutic trial of ICSs for young children with non-specific chronic cough is not ideal, but results from an imprecise definition of asthma and lack of available tests to confirm a diagnosis of asthma in young children. Before starting ICS therapy, therefore, a definite period of treatment (e.g.,2-4 weeks for high-dose ICS, and 8-12 weeks for conventional dose ICS) and objective endpoints should be set. If there is a response and ICS treatment has subsequently been stopped, asthma is suggested by an early relapse that again responds to ICSs.

Use of Leukotriene Receptor Antagonists (LTRAs) for Treatment of Non-Specific Chronic Cough

Recommendation for adults

For adults with non-specific CC, the guideline suggests against the empirical use of LTRAs. Short-term ICS therapy is a preferred option over LTRAs as empirical treatment targeting asthmatic cough in non-specific chronic cough. However, LTRAs might be more suitable for patients with difficulty in using inhalers. As with the use of ICSs, objective documentation of an asthmatic or an eosinophilic cough justifies long-term treatment. Otherwise, only short-term (2-4 weeks) treatment is recommended.

Recommendation for children

Currently, there is no reliable evidence to draw definite recommendations. When using LTRAs in children with non-specific chronic cough, careful considerations of cost and risk/benefits are needed until there is sufficient data to determine the efficacy of LTRAs in these children. Given the morbidity rate associated with non-specific chronic cough, evaluations are needed to assess the efficacy and safety of LTRAs for non-specific chronic cough in children.

Use of Proton Pump Inhibitors (PPIs) for Treatment of Non-Specific Chronic Cough

For adults with non-specific CC, the guideline suggests against the empirical use of PPIs.

DIAGNOSTIC TEST FOR CORTICOSTEROID-RESPONSIVE COUGH IN CHRONIC COUGH

Use of Fractional Exhaled Nitric Oxide (FeNO) Measurement for Prediction of Asthma in Chronic Cough

Recommendation for adults

For adults with CC, we suggest the use of FeNO measurement to predict asthma. FeNO measurement may be particularly useful when conventional diagnostic tests for asthma (such as methacholine challenge) are not available or patients have difficulty in performing the tests. However, it should be noted that the utility of FeNO is just to characterize the nature of airway inflammation (and thus can predict the anti-inflammatory treatment responses), but is not to confirm the diagnosis of asthma. Asthma is increasingly recognized as a heterogeneous condition and is not definable by the presence of type 2 inflammation alone. Elevated FeNO levels in CC patients with normal chest X-rays may suggest not only cough variant asthma but also eosinophilic bronchitis. In addition, unlike in patients diagnosed as asthma, there is no sufficient evidence to suggest optimal duration for anti-inflammatory treatment in chronic cough patients with high FeNO levels.

Recommendation for children

For children with CC, the guidelines suggest the use of FeNO measurement to predict asthma. FeNO measurement may be particularly useful for younger patients who find it difficult to perform the bronchial challenge test. However, it should be noted that FeNO levels well reflect airway inflammation, but do not directly indicate a diagnosis of a specific disease.

EMPIRICAL ANTIBIOTICS FOR CHRONIC WET COUGH IN CHILDREN

Use of Empirical Antibiotics for Treatment of Children with Chronic Wet or Productive Cough

For children with chronic wet cough, the empirical administration of appropriate antibiotics for a period of 2 weeks, especially in children aged <6 years is recommended. Antibiotic selection should be based upon local sensitivity patterns. However, the proposed criteria for protracted bacterial bronchitis (PBB) are non-specific and may lead to substantial overdiagnosis. If chronic wet cough fails to respond to antibiotics, then further investigations are required to rule out other chronic suppurative lung diseases.

TREATMENT FOR UNEXPLAINED CHRONIC COUGH IN ADULTS

Use of Opioids for Treatment of Unexplained Chronic Cough

For adults with unexplained chronic cough, the use of low-dose opioids to control cough is suggested. Currently, codeine is the only approved opioid for anti-tussive use in Korea. Due to frequent side effects, careful consideration of the benefit-harm balance is recommended. The long-term benefits and harms warrant further investigations.

Use of Neuromodulators for Treatment of Unexplained Chronic Cough

For adults with unexplained chronic cough, the use of low-dose opioids to control cough is suggested. Currently, codeine is the only approved opioid for anti-tussive use in Korea. Due to frequent side effects, careful consideration of the benefit-harm balance is recommended. The long-term benefits and harms warrant further investigations.

Use of Multi-Dimensional Behavioral Therapy for Treatment of Unexplained Chronic Cough

For adults with unexplained chronic cough, the use of multi-dimensional behavioral therapy (or speech pathology therapy) is suggested. At present, there is no standardized protocol for Korean patients.

For more information follow the link: https://doi.org/10.4168/aair.2018.10.6.591