Child and Chest Health Care Delhi NCR

Asthma,only as cough

Asthma is a leading cause of respiratory morbidity all over the world whether it be adult or children.In cough variant asthma,patients have only symptom of troublesome cough for a long period.They do not complaint of tightness of chest,difficulty in breathing,or wheezing any time in the course of their illness.On CHEST auscultation,there is no adeventitious sound in the form of wheeze.This type of cough presents a difficulty in front of treating physician for the accurate diagnosis.It may be asthma or other diagnosis which needs meticulous investigations.It is also difficult to convince to patients or parents that it may be asthma,because there is a common belief among patients and parents that asthma means difficulty in breathing.On the other hand,spirometry,which is a goldstandard diagnostic test for asthma, done on such type of asthma patients are usually normal.

FeNO(Fractional excretion of nitric oxide) is measured by a portable machine,which is hand held and subject is asked to exhale through the mouth piece connected to a hand held device.The measurement is in part per billion(ppb).The normal and abnormal levels have been validated in adults,not in children.But its level when it is high,well correlates with eosinophilic inflammation of airways in children and it can be performed easily in school going children.

In a study ,32 patients with an average age of 42.5 years were included.All had only cough for a long period(chronic cough),normal blood eosinophil count,normal chest X-Ray,normal spirometry results but abnormal ACT(Asthma control test) and positive skin prick test for environmental antigens.9 healthy persons were included for control with the mean age of 47 years.FeNO measurements were taken with the help of FeNO analyser.

FeNO were significantly elevated with the mean value of 64.4ppb in 91%(n29) of patients.The normal cut off value for adults is 25ppb.In healthy controls,the mean value measured was 16ppb.

REFERENCES:Nsouli T, Diliberto N, Nsouli S, Zamora S, Nsouli A, Bellanti J. Lack of concordance between FeNO and spirometry in patients with chronic cough. Presented at: American College of Allergy, Asthma, & Immunology Annual Scientific Meeting 2019; November 7-11, 2019; Houston, TX. Abstract A202

Sometimes ,it becomes difficult to differentiate asthma,COPD and asthma-COPD overlap

It is easy to take sputum sample in adult, but in children it is difficult

So,any sample can be used depending upon the age of patient,if both correlates well

Researchers from Japan retrospectively,evaluated 195 patients with Asthma(n95),COPD(n61) and asthma COPD overlap(n39) between 2015 to 2017

Sputum sample was centrifuged at 500g for 5 minutes,then transferred to a glass slide.It was then crushed with a rotatory motion with another glass slide.Cell counts were done after proper staining.

To assess whether the sputum eosinophil counts-/>3% correlates with blood eosinophil count,researchers constructed ROC(Receivers operative curve)

Patients with Asthma and asthma COPD overlap had significantly higher eosinophil count and lower neutrophil counts during stable period as compared to patients with COPD . But it was not so during exacerbations.

MEAN eosinophil and neutrophil counts: asthma, 17.4% and 78.8%, respectively; COPD, 1.8% and 95.6%, respectively; and asthma-COPD overlap, 11.8% and 84.2%, respectively).It was during stable period

But,during the periods of exacerbation, following was the results

MEAN eosinophil and neutrophil counts: asthma, 15.0% and 83.3%, respectively; COPD, 4.8% and 86.4%, respectively; and asthma-COPD overlap 17.7% and 79.9% respectively.

There was significant correlations between blood and sputum eosinophil percentage among all categories of patients both during stable and during the period of exacerbations

It was clear from the analysis of ROC curve, that the blood eosinophil can predict sputum eosinophil count3% during stable period as well as during the period of exacerbations.Following is the results.

During stable period  (AUC, 0.75 [95% CI, 0.66-0.84]; cutoff, 235 µL; sensitivity, 75.4% and specificity, 71.3%) and during the exacerbation period (AUC, 0.80 [95% CI, 0.66-0.94]; cutoff, 351 µL; sensitivity, 61.1% and specificity, 97.1%).

So  we can take either sample according to feasibility and during the stable period ,we can diffferentiate between asthma,COPD and asthma COPD overlap

REFERENCES:

Tamura K, Shirai T, Hirai K, et al. Differentiation of asthma, COPD, and asthma-COPD overlap via a simplified sputum cell count method. Presented at: CHEST Annual Meeting 2019; October 19-23, 2019; New Orleans, LA. Abstract 464.