A study of eosinophil count in nasal and blood smear in allergic respiratory diseases in a rural setup.
Allergic respiratory disorders are fairly common visiting cases in
pediatrics outpatient department (OPD). With an appropriate history and
detailed examination, diagnosis may not be problematic. Routine
investigation may not contribute much to the final diagnosis but may
help in ruling out other possibilities. This study was done to evaluate
sensitivity and specificity of blood or nasal eosinophilia in subjects
suffering from allergic respiratory disorders and also to assess the
feasibility of nasal cytogram which is a simple, economical and reliable
investigation in allergic respiratory disorders. This is a prospective
clinical correlation study of patients attending outpatient department.
100 subjects aged between 2-18 years of either sex were selected for the
estimation of eosinophil count in nasal and peripheral smear in allergic
respiratory disorders. All allergic respiratory cases based on
eosinophillia. The nasal and blood eosinophilia were compared with each
other and clinical findings of allergic rhinitis with or without asthma
were studied. In this study peak age incidence was seen between 11-18
years and it was more common in males. Rhinorrhoea, pale mucosa and
nasal obstruction were common findings in allergic rhinitis with
bronchial asthma. Nasal eosinophilia was seen in 52.4% and 64.9% of
cases of allergic rhinitis and allergic rhinitis with asthma
respectively. Blood eosinophilia was seen in 54% and 56.8% of cases of
allergic rhinitis with asthma respectively. Nasal cytogram which is a
simple, economical and non- invasive procedure can be used as an
alternative to invasive peripheral smear eosinophilia as both are
equally efficacious in diagnosing allergic respiratory diseases.
KEY WORDS: Eosinophilia; Allergic rhinitis; Bronchial asthma
Asthma (Care and treatment)
|Publication:||Name: Internet Journal of Medical Update Publisher: Dr. Arun Kumar Agnihotri Audience: Academic; Professional Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2012 Dr. Arun Kumar Agnihotri ISSN: 1694-0423|
|Issue:||Date: Jan, 2012 Source Volume: 7 Source Issue: 1|
|Topic:||Event Code: 310 Science & research|
|Geographic:||Geographic Scope: India Geographic Code: 9INDI India|
Hay fever (allergic rhinitis) and asthma are two very common allergic diseases of the respiratory tract (1). The two have much in common as to age at onset, seasonal manifestations, and causation. Hay fever involves the mucosa, or lining of the upper respiratory tract only, whereas asthma is confined to the bronchial tubes of the lower respiratory tract (2).
There is mounting evidence that eosinophils are implicated in pathophysiology of allergic respiratory diseases, the direct and easy access of airborne allergens and irritants to the airways stimulate mast cells to produce IgE and cytokines which serves as enhancing factors for eosinophilic infiltration in allergic diseases (3). Since allergic rhinitis and asthma are such prominent disorders of immediate hypersensitivity, it is not surprising that identification of eosinophil leukocytes within the nasal and bronchial mucosa and corresponding eosinophilia of the nasal secretion and sputum are common findings in atopic populations (4).
In the geographical area where allergens are prevalent, their role as the etiological factor is higher in allergic respiratory disorders (5). Confirmation of allergen as etiologic agent is difficult in a small setup, where IgE estimation and allergy tests are not accessible (6).
This study was done to evaluate sensitivity and specificity of blood or nasal eosinophilia in subjects suffering from allergic respiratory disorders and also to assess the value of nasal cytogram as an alternative investigation.
This was a prospective clinical correlation study conducted from 2008 to 2010, of 100 children between 2 to 18 years of either sex, with typical history and clinical features of allergic respiratory diseases who attended the outpatient department of Pediatrics. Children with tuberculosis, recurrent and chronic pneumonia, malnutrition, malignancy, collagen vascular disorders and those who were on steroid therapy were excluded from the study. The history, clinical features and investigation were noted in a proforma specially designed for the study. The following investigations were done: blood studies, nasal discharge smear for eosinophil count, Mantoux test and chest X-ray in all children included in the study. Consents from the parents and institutional ethical committee clearance were obtained.
Nasal and peripheral smear examination was done as follows:
Nasal Smear Preparation
Nasal secretion was collected by asking the child to blow his nose into a plastic wrap and then placed on a glass slide. If he was too young to do this or insufficient secretion was obtained, cotton tipped swab was inserted into a nostril and left for 60 seconds. The nasal secretion which was obtained was transferred onto a glass slide, teased out and allowed to air dry.
With strict aseptic precautions, blood sample was drawn by venepuncture and 3 ml of blood was collected in Ethylene Diamine Tetra Acetic Acid (EDTA) anticoagulant. The sample collected was subjected to investigations like Hb%, Total Count (TC), Differential Count (DC), Erythrocyte Sedimentation Rate (ESR), Absolute eosinophil count (AEC), and peripheral smear examination.
Peripheral smear preparation
A small drop of blood was placed about 1 or 2 cm from one end of a pre-cleaned slide and immediately another slide with a pre-cleaned edge was placed at an angle of 25 degrees and moved backwards to make contact with the drop. The drop of blood was spread quickly along the line of contact of spreader with the slide and allowed to air dry. Peripheral blood smear was studied using Leishman's stain whereas nasal smear was studied by Haematoxylin and Eosin (H & E) stain.
The following methods of statistical analysis have been used in this study, Chi-square test Student "t" test, Sensitivity, specificity positive predictive value, negative predictive value. Data analysis was carried out using Statistical Package for Social Science (SPSS Ver. 10.5).
A total of 112 patients presented to outpatient department of paediatrics during the study period with history suggestive of allergic rhinitis. 12 of them were excluded from the study because of associated malnutrition, pneumonia, tuberculosis or steroid therapy. The results of analysis of data of 100 study cases were as follows. 35% of the allergic respiratory cases were in the age group>15 years, among this 63% of the cases were of adolescent group (aged between, 11-18 years). The incidence of allergic disorder was more common in males (62%) compared to females (38%). Female: Male Ratio= 1:1.6 (Table 1a & b).
In this study dust was the most common risk factor for allergic rhinitis accounting for 81% followed by weather changes 62%, whereas in allergic rhinitis with bronchial asthma, weather change is a common risk factor accounting for 94%, followed by dust (73%) and family history (64%) (Table 2). In this study the most common sign and symptom was rhinorrhoea (100%) in both the groups followed by nasal obstruction (81%) (Table 3) The mean nasal eosinophil in allergic rhinitis (20.10 cells) and bronchial asthma (20.19 cells) were almost similar, and the mean blood eosinophil count in allergic rhinitis with asthma (589) was higher than in allergic rhinitis (506) but this was statistically not significant (p=0.270) Table 4. In this study all 100 cases were investigated for both nasal and blood eosinophil count. The positive nasal eosinophilia (>10cells) cases were 57%. Similarly, the positive blood eosinophilia (>440 cells/cc mm) were 55%. Nasal eosinophilia is more common in allergic rhinitis with asthma compared to only allergic rhinitis (64.9 vs. 54.5) but this was statistically not significant (p>0.223) Table 5a. Blood eosinophilia is almost similar in allergic rhinitis with asthma compared to only allergic rhinitis (56.8 vs. 54.0) but statistically not significantly (p>0.787) (Table 5b).
In this study we compared the correlation between nasal smear and peripheral blood eosinophils in allergic rhinitis patients with or without asthma. There was a positive correlation between nasal and peripheral blood smear eosinophilia in allergic rhinitis patients with asthma (Table 6a). Children with only allergic rhinitis had significant nasal eosinophilia showing that nasal smear eosinophilia is more reliable in this group (Table 6b).
The sensitivity of nasal eosinophilia is higher in allergic rhinitis with bronchial asthma compared to other group (85.7 vs. 73.5) (Table 7).
Allergic respiratory disorders are fairly common cases in pediatrics outpatient department (OPD). With an appropriate history and detailed examination the diagnosis is usually not
problematic. Routine investigations may not contribute much to the final diagnosis but may help in ruling out other possibilities. To confirm the allergic nature of the disease complicated tests like IgE, skin tests, (RAST) Radio Allergosorbent Test, (ELISA) Enzyme Linked Immuno Sorbent Assay etc, may not be possible in many hospital setups. Hence, a simple test for finding out allergy as an etiological agent by doing eosinophils count in nasal and peripheral blood smear and establishing it as a reliable and simple investigation has been tried.
In this study, majority of the allergic respiratory cases visiting paediatric OPD were of adolescent age group (11-18 years) accounting for 63% with male predominance. This finding was supported by Mirsaid Ghazi et al (7), who showed in their study that the incidence of allergic rhinitis in children increases with age and there was male predominance. The most common associated factor in patients with allergic rhinitis without bronchial asthma was dust exposure accounting for 81%, followed by weather change (62%); whereas in patients of allergic rhinitis with bronchial asthma weather change was the most common associated factor accounting for 94% followed by dust in 73% and family history in 64% of patients. Among 100 children, 49 had a family history of allergic respiratory disorder out of which bronchial asthma cases were significantly more, accounting for 64.8% and this is comparatively more than the observation made by Chowdary et al (50%) (8). Among other risk factors, food allergy and pet animal history was found in 27% and 18% of patients respectively. This observation was higher when compared to the study of Pokharel et al (6% and 12%) (9).
In this study, all the children with allergic rhinitis had rhinorrhoea (100%) which is also high in other studies done by Akbari et al10 and Mirsaid Ghaz et al (7) (92% and 73.4%). Pale mucosa is the next common clinical finding accounting for 84% which is similar to Akbari et al (10) accounting for 88%. Following this, nasal obstruction and sneezing were the next presenting finding. Among all clinical findings, symptoms contributed more than signs to the diagnosis.
Nasal eosinophil and blood eosinophil count was done in all (100) cases and nasal eosinophil count of >10 cells were considered as positive as per IAP text recommendation (11). Many studies have taken different cut-off values. Sanil et al (12) and Crobach et al (13), etc have considered >10 cells as significant similar to the present study. Similarly, blood eosinophil count >440 cell/cumm is considered as significant and this cut-off value is also considered by Chowdary et al (8).
Various workers have found varying results for nasal smear eosinophilia, ranging from 18% to 81%. This study correlates well with Sanil et al (57%)12. The mean absolute number of blood eosinophils in both groups totaling 100 patients was 537.07/cu mm and the mean value for eosinophils in the nasal secretions was (20.13.) When compared with both the groups the children with allergic rhinitis with asthma showed slightly higher blood eosinophils (588.9/cumm) than those with allergic rhinitis alone (506.6), which was similar to Saracli et el (14). However this difference was not statistically significant. Correlation between nasal smear and peripheral blood eosinophils in allergic rhinitis patients with or without asthma showed that out of 45 cases with AEC counts less than 440/cu mm, 16 (28.1%) showed increased nasal eosinophils. Whereas 55 children with AEC counts more than 440/cu mm, 41(71.9%) showed increased nasal eosinophils. Thus, there is positive correlation between nasal and peripheral blood smear eosinophilia. In children having only allergic rhinitis (63 cases), 33 showed significant nasal eosinophilia (>10/HPF), of which 25 (75.8%) showed increased peripheral smear eosinophils.
Out of 34(54%) cases which had blood eosinophilia >440/cu mm, of which 25 (73.5%) patients showed nasal smear eosinophilia >10 cells. In 63 children having allergic rhinitis with bronchial asthma, 26(70.3%) showed positive nasal eosinophilic count, of which 18 (69.2%) had peripheral smear eosinophilic count. Out of 21 (56.8%) cases with peripheral smear eosinophilia 18 (85.7%) showed nasal smear eosinophila. Hence, nasal smear eosinophila was more reliable in this group.
We like to conclude that peripheral eosinophilia contributes equally in diagnosing allergic rhinitis and bronchial asthma, whereas nasal eosinophilia contributes more in diagnosing bronchial asthma than allergic rhinitis. In children with allergic rhinitis with or without bronchial asthma, there is positive correlation between nasal and peripheral smear eosinophilia.
Hence, nasal cytogram which is a simple, economical and non-invasive procedure can be used as an alternative to invasive peripheral smear eosinophilia as both are equally efficacious in diagnosing allergic respiratory diseases.
(1.) Porter P, Polikepahad S, Qian Y, et al. Respiratory tract allergic disease and atopy: experimental evidence for a fungal infections etiology. Med Mycol. 2011 Apr;49 Suppl 1:S158-63.
(2.) Bhattacharyya N, Kepnes LJ. Additional disease burden from hay fever and sinusitis accompanying asthma. Ann Otol Rhinol Laryngol. 2009 Sep;118(9):651-5.
(3.) Bloemen K, Verstraelen S, Van Den Heuvel R, et al. The allergic cascade: review of the most important molecules in the asthmatic lung. Immunol Lett. 2007 Oct 31;113(1):6-18.
(4.) Amorim MM, Araruna A, Caetano LB, et al. Nasal eosinophilia: an indicator of eosinophilic inflammation in asthma. Clin Exp Allergy. 2010 Jun;40(6):867-74.
(5.) Schwartz DA. Gene-environment interactions and airway disease in children. Pediatrics. 2009 Mar;123 Suppl 3:S151-9.
(6.) Shinogi J, Majima Y, Takeuchi K, et al. Quantitative cytology of nasal secretions with perennial allergic rhinitis in children: comparison of noninfected and infected conditions. Laryngoscope. 1998 May;108(5):703-5
(7.) Mirsaid Ghazi B, Imamzadehgan R, Aghamohammadi A, et al. Frequency of allergic rhinitis in school-age children (7-18 Years) in Tehran. Iran J Allergy Asthma Immunol, 2003 Dec;2(4):181-4.
(8.) Chowdary VS, Vinaykumar EC, Rao JJ, et al. A study of serum IgE and eosinophils in respiratory allergy patients. Indian J Allergy Asthma Immunol. 2003;17(1):21-4
(9.) Pokharel PK, Pokharel P, Bhatta NK, et al. Asthma symptomatics school children of Sonapur. Kathmandu Univ Med J (KUMJ). 2007 Oct-Dec;5(4):484-7.
(10.) Akbari H, Fana-Hosseini R, Miri S, et al. The prevalence of allergic rhinitis among 11-15 years old children in Shiraz. Iranian J Immunol. 2004;1(2):133-7.
(11.) Atkins D, Donald ML: Diagnosis of allergic disease. Nelson text book of pediatrics; 19th edition: 2010:741-51.
(12.) Sanil A, Aydin S, Ates G, et al. Comparison of nasal smear eosinophilia with skin prick test positivity in patients with allergic rhinitis. Kulak Burun Bogaz Ihtis Derg. 2006;16(2): 60-3.
(13.) Crobach M, Hermans J, Kaptein A, et al. Nasal smear eosinophilia for the diagnosis of allergic rhinitis and eosinophilic nonallergic rhinitis. Scand J Prim Health Care. 1996 Jun;14(2):116-21.
(14.) Saracli T, Scott RB. Comparative study of simultaneous blood and nasal secretion eosinophilia in children with allergic diseases. J Asthma Res. 1967 Mar;4(3):219-27.
Naveen Kumar * MD, Kiran Bylappa ([PSI]) ([dagger]) MS, Ramesh AC ([double dagger]) MD and Swetha Reddy ** MBBS
* Assistant Professor, Department of Pediatrics, Sri Devarj Urs Medical College & Hospital. Tamaka, Kolar, Karnataka, India
([dagger]) Assistant Professor, Department of Otorhinolaryngology, Sapthagiri Institute of Medical Sciences & Research Center, Bengaluru, Karnataka, India
([double dagger]) Professor, Department of Pediatrics, Kempegowda Institute of Medical Sciences, Bengaluru, Karnataka, India
** Junior Resident, Department of Pediatrics, M. R. M. C. Gulbarga, Karnataka, India
(Received 18 January 2011 and accepted 03 March 2011)
([PSI]) Correspondence at: #24, 7th main road Vasanthanagar, Bangalore 560052, Karnataka, India; Mobile: 09945690149; Email: firstname.lastname@example.org
Table 1a: Age distribution Age (in yrs) Frequency Percent 2-5 19 19.0 6-10 18 18.0 11-15 28 28.0 >15 35 35.0 Total 100 100.0 Table 1b: Sex incidence Sex Frequency Percent Male 62 62.0 Female 38 38.0 Total 100 100.0 Female: Male Ratio = 1:1.6 Table 2: Distribution of risk factors Allergic Rhinitis Allergic Rhinitis with (n=63) bronchial asthma (n=37) Risk Factor Frequency Percent (%) Frequency Percent (%) Dust 51 81.0 27 73.0 Weather change 43 68.3 35 94.6 Animal 9 14.3 9 24.3 Food 10 15.9 17 45.9 H/o Family atopy 25 39.6 24 64.8 Table 3: Distribution of signs and symptoms Allergic Rhinitis Allergic Rhinitis with bronchial (n=63) asthma (n=37) Symptoms and symptoms Frequency Percent Frequency Percent Rhinorrhoea 63 100.0 37 100.0 Nasal itching 24 38.1 16 43.2 Nasal obstruction 51 80.9 24 64.8 Pale mucosa 53 84 30 81.0 Sneezing 32 50.8 12 32.4 Cough 23 36.5 37 100.0 Wheezing 1 1.6 37 100.0 Dyspnea 0 0 12 32.4 Fever 8 12.7 4 10.8 Table 4: Distribution according to mean Diagnosis n Mean SD Minimum Nasal Allergic Rhinitis 63 20.10 22.230 0 Eosinophils Allergic Rhinitis 37 20.19 18.017 0 with Bronchial Asthma Total 100 20.13 20.677 0 Blood Allergic Rhinitis 63 506.60 351.066 95 Eosinophils Allergic Rhinitis 37 588.95 370.256 86 with Bronchial Asthma Total 100 537.07 358.654 86 't' 'p' Diagnosis Maximum value value Nasal Allergic Rhinitis 80 0.000 >0.983 Eosinophils Allergic Rhinitis 80 with Bronchial Asthma Total 80 Blood Allergic Rhinitis 1888 1.232 >0.270 Eosinophils Allergic Rhinitis 1650 with Bronchial Asthma Total 1888 Table 5a: Distribution of nasal eosinophils according to the diagnosis Nasal Allergic Allergic Rhinitis with eosinophils Rhinitis bronchial asthma Total <10 30 (47.6%) 13 (35.1%) 43 (43.0%) [greater than 33 (52.4%) 24 (64.9%) 57 (57.0%) or equal to] 10 Total 63 (100.0%) 37 (100.0%) 100 (100.0%) Chi-Square Value df 'p' value 1.482 1 .223 Table 5b: Distribution of blood eosinophils according to the diagnosis Blood Allergic Allergic Rhinitis with eosinophils Rhinitis Bronchial Asthma Total [less than or 29 (46.0%) 16 (43.2%) 45 (45.0%) equal to] 440 >440 34 (54.0%) 21 (56.8%) 55 (55.0%) Total 63 (100.0%) 37 (100.0%) 100 (100.0%) Chi-Square Value df 'p' value 0.073 1 .0.787 Table 6a: Correlation between nasal and blood smear eosinophil counts in allergic rhinitis and allergic rhinitis with bronchial asthma Blood eosinophil Nasal [less than or eosinophil >440 equal to] 440 Total [greater than 41 (71.9) 16 (28.1) 57 (100) or equal to] 10 <10 14 (32.6) 29 (67.4) 43 (100) Total 55 (55) 45 (45) 100 (100) Sensitivity Specificity PPV NPV Accuracy Nasal eosinophil 74.5 64.4 67.4 71.9 70 [greater than or equal to] 10 <10 Total Figures in parenthesis indicate percentage. Table 6b: Correlation between nasal and blood smear eosinophil counts in allergic rhinitis without bronchial asthma Blood eosinophil Nasal [less than or eosinophil >440 equal to] 440 Total [greater than 25 (75.8) 8 (24.2) 33 (100) or equal to] 10 <10 9 (30) 21 (70) 30 (100) Total 34 (54) 29 (46) 63 (100) Sensitivity Specificity PPV NPV Accuracy Nasal eosinophil 73.5 72.4 70 75.8 73 [greater than or equal to] 10 <10 Total Figures in parenthesis indicate percentage. Table 7: Correlation of allergic rhinitis vs. allergic rhinitis with asthma Allergic Allergic rhinitis with rhinitis (%) asthma (%) Sensitivity 73.5 85.7 Specificity 72.4 50 PPV 70 69.2 NPV 75.8 72.7 Accuracy 73 70.3
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