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Sensitization to pollen , animal dander , house dust mites and moulds among patients with allergic rhinitis in warm dry climates Abbas H. Alsaeed M Med Sci, PhD, CLC, MRCpath Assistant Professor and Consultant Hematologist King Saud University, College of Medical Sciences Dept. Of Clinical Laboratory Sciences 1 Variations in Defining Allergic Rhinitis 1. 2. 3. Allergic rhinitis was defined as the selfreported presence, in the previous year, of usual nasal blockage and discharge apart from colds or the flu, provoked by allergens, with or without conjunctivitis (Ng & Tan, 1994) Rhinitis was defined as sneezing or a runny or blocked nose not due to a cold or the flu (Sly, 1999) Individuals with rhinitis were defined as those suffering with three or more symptoms of rhinitis either throughout the year (perennial) or for part of the year (seasonal) (Frosh et al 1999) 2 Background Pollutants have a direct effect on the nose by causing cellular damage and stimulating the release of inflammatory mediators (Bascom, 1991). Prevalence rates of rhinitis symptoms among office workers reported in the western countries were around 30%, but could be as high as 60% in some offices (Finnegan 1984; Viegi et al 1991) 3 ANIMAL EPITHELIA DANDERS 1-Cats are considered to be the most highly allergenic animal species for most people. 2-Dog, responsible for allergens, usually specific to epithelial proteins. 3-Horse is reported as a source of a very potent allergen. Many patients develop severe allergy, even an indirect contact to horse is enough to release symptoms. 4 HOUSE DUST MITES (HDM) Dust mites are microscopic organisms, belong to the kingdom animalia, phylum arthropoda and class arachnia. The organism’s genus and species name are Dermatophagoides pteronyssinus and Derm. farinae. HDM is widely suspected to be an important factor in the pathogenesis of allergic disease . 5 MOULD Mould, e.g. alternaria alternata is a common and cosmopolitan species occurring on many plants and other substrates including soils, food and textiles. It is frequently found on condensed window frames and it considered an outdoor mould and appears when weather is warm. A. alternata is considered one of the most allergenic mould in the world (Agarwal et al 1982). 6 Symptoms of Allergic Rhinitis 1- Sensitive to specific allergens, e.g. dust 2- Pruritus of the nose, eyes palate, ears 3- Sneezing more than two at a time 4- Watery rhinorrhoea 5- Coexistant asthma or eczema 6- Seasonal symptomas 7- Family history of allergies. 7 Classification Allergic Rhinitis Seasonal Allergic Rhinitis (Hayfever) (SAR) Perennial Allergic Rhinitis (PAR) Occupational Allergens Pollen from a variety of trees, grasses, and weeds. HDM, Mold, Animal epithelial dander, Food (rare) Chemicals 8 Perennial Allergic Rhinitis (PAR) Patients with PAR are more likely than those with SAR to have asthma (Kubetin 2001). Positive family history of allergic rhinitis. Personal history of collateral allergy such as eczematous dermatitis, urticaria, and/or asthma. 9 Non-allergic Triggers Cold air 2. Smoke and perfumes 3. Strong odors 4. Spicy/hot food 5. Alcohol 6. Pregnancy / hormones 7. Decongestant nasal sprays 8. Medications, e.g. antihypertensive agents (Druce 1998). 1. 10 Symptoms of non-allergic rhinitis 1. 2. 3. 4. History of negative allergen specific IgE test Sensitive to temperature changes, smoke, perfume or environmental irritants Adult onset of symptoms Nasal crusting or drying. 11 Common Comorbidity Perennial Seasonal Sinusitis 50% 23% Asthma 22% 16% Otitis Media 14% 14% 20-15% of allergic rhinitis patients had asthma 75-80% of asthma patients had allergic rhinitis (Kirn 2001). 12 AIMS 1- To investigate sensitization to pollen, animal dander, HDM and mould in adult patients with allergic rhinitis in warm dry climates using an immunoblot assay. 2- To estimate the prevalence of rhinitis symptoms in warm climate. 3- To study the relationship between rhinitis symptoms and allergens. 13 Subjects Thirty–eight adult patients (25 males and 13 females) with diagnosed allergic rhinitis without a previous history of treatment attending the outpatient ENT clinic, from April 2002 to March 2005 on General Hospital, Saudi Arabia. 14 Investigations History: present illness, past medical history, family history, environmental history, and impact on quality of life. 2. Physical exam: nose, eyes, ears, lung, skin. 3. Nasal exam with rhinoscope / flexible nasendoscope. 4. Nasal smear for eosinophils. 5. Nasal mucociliary clearance assessment: saccharin test, and ciliary best frequency measurement. 6. Nasal airway assessment. 7. Allergy tests: Allergen specific IgE 1. 15 Allergy Test (Methods) METHOD TEST Blood Test allergen immunoblot assay (RIDA allergen screen) Blood serum is combined with allergen in trough Radio-allergosorbent allergy Blood serum is testing (RAST) combined with allergen in test tube. Skin Test Provocation testing Direct exposure (e.g. via inhalation or ingestion to a likely allergen Prick testing Percutaneous Scratch testing Percutaneous Intradermal testing Intradermal injection 16 METHOD Allergens are coated to the surface of nitrocellulose membranes lying in trough. Patient serum pipette into the reaction trough. Allergy screen detection antibody were added. Streptavidin conjugate with alkaline phosphatase that binds to biotin in the test fields were added. 17 Continue Substrate a specific enzyme color reaction of alkaline phosphatase were added. The reaction stopped by rinsing with water and analysis the results on the test strips (RIDA allergy screen 2002). Negative control had not been coated with allergen, biotin-labeled bovine serum albumin had been applied as positive control. The color intensity on the test fields is directly reflect to specific IgE antibody in the serum of the patients. 18 Figure (1) Illustrates the results appearance on the surface of nitrocellulose membrane 19 Results Specific IgE antibodies were detected in 65.8% of all the subjects . Males demonstrated a higher rate than females (76% vs. 46.2%) or a M/F ratio of ~ 2:1. Parameters Number Allergen Allergen Absent (%) Present (%) P value Patients 38 13 (34.2%) 25 (65.8%) < 0.005 Male 25 06 (24.0%) 19 (76.0%) < 0.005 Female 13 07 (53.8%) 06 (46.2% 0. 5 20 Continue Results The sensitization rate was highest for pollen while results for the other allergen groups are as follows : pollen (68.3%), animal dander (23.9%), HDM (6.0%), and moulds (1.8%). Among allergenic pollen mixed grasses were the most common cause of sensitization (11.1%) while alder, birch, rye and oak have the same, albeit lower sensitization rates (9.4%). These plants are commonly cultivated for greening purposes in urban areas . 21 Continue results Sensitization rate to cat and dog dander are (9.4% and 8.5% respectively), while dander from horse, guinea pig and golden hamster caused lower rates of sensitization (3.4% - 1.7%). Dermatophagoides pteronyssinus and Dermatophagoides farinae are the most prevalent indoor sensitizers (4.3% and 1.7%, respectively). Sensitization to mould is relatively rare ( 1.8%). 22 Animal dander (23.9%) and HDM (6.0%) altogether pose a significant although less important source of exposure, with only rare cases involving mould (1.72%), leaving pollen as the leading cause of sensitization, attributable in part to the all too common utilization of plants in urban areas (like Riyadh) which are purposely cultivated for greening purposes and in part to existing dry climatic conditions 23 Table (2) Distribution of allergen antibodies in rhinitis patients. Allergen (antigen system) Pollens (Aeroallergens) Alder Birch Hazel Grasses Rye Mugwort Plantain Oak Allergen Antibodies No. Allergen Antibodies Antibodies (%) System (%) 68.3 11 11 10 13 11 8 5 11 9.4 9.4 8.5 11.1 9.4 6.8 4.3 9.4 Animal epithelia dander Cat Horse Dog Guinea pig Golden Hamster Rabbit 23.9 11 4 10 1 2 - 9.4 3.4 8.5 0.9 1.7 24 Allergen (antigen system) Allergen Antibodies No. Allergen Antibodies (%) House dust Mites Derm. pteronyssinus 2 1.7 Derm. farinae 5 4.3 Mould Alternaria alternate Pencillium notatum Cladosporium hebarum Antibodies System (%) 6.0 1.8 - - Aspergilus fumigatus 1 1 0.9 0.9 Total 117 100 100 25 Figure ( ) Diagram showing the overlapping of sensitization to combination of allergens (%) among patients with allergic rhinitis 26 Allergic patients are not only allergic to one sole type of allergen since many of them will display sensitization to a combination of allergens . The largest subset of patients display a combination of sensitization to both pollen and dander 27 Table (3) Patients with one or multiple allergen antibodies developed No. of allergen Antibodies developed No. of patients and percentage Sensitized patients (Percentage) 1 06 (15.8%) 24 % 2 01 (2.6%) 4% 3 03 (7.9%) 12 % 4 02 (5.3%) 8% 5 03 (7.9%) 12 % 6 03 (7.9%) 12 % 7 01 (2.6%) 4% 8 04 (10.5%) 16 % 9 01 (2.6%) 4% 11 01 (2.6%) 4% Total 65.1 100 28 In most studies the prevalence of seasonal allergic rhinitis is significantly higher than perennial allergic rhinitis , and range from 4.5 % to 38.3 % (Charpin et al 1993; Dotterud et al 1994) . In Finland the prevalence of allergic rhinitis is around 14% (Pekkanen et al, 1997). in Australia 27% ( Woolcock et al 2001), while in India 20-30% of the general population suffers from allergic rhinitis (Anonymous, 2000). In the United States allergic rhinitis seems to be exceedingly common where 9-40% of the population may have some form of allergic rhinitis at anytime of the year 29 Figure (2) Relative prevalence of allergens & seasons: the allergen clender 12 % Cases No. 10 8 6 4 2 0 Winter Spring Pollens Dander Summer HDM Autumn Moulds 30 In a related study in Ankara, Turkey, grass pollen were found to be the major allergens in a study by Sener et all (2003). In Kuwait, higher sensitization rates were seen among pollen belonging to plants which were imported from other countries for shading purposes or for binding sand, like Chenopedium and Bermuda grass (Dowalsan et al, 2000). In most European and North American countries allergens with the highest sensitization rates among patients with nasal symptoms were also pollen/aeroallergens followed by house dust mites and cat dander 31 HDM were reported to have the highest rate of sensitization among patients with allergic rhinitis in Thailand (Pumhirum et al, 1997), Singapore (Chow et al, 1999) and in Taiwan especially among asthmatic patients (Tsai et al, 1998). 32 Report of Prevalence Rates in Allergic Rhinitis (variation in methodology) Prevalence Age Country Year 24.0% 62.5% 51.0% 27.6% 41.5% 22.0% 15.9% 26.3% UK Turkey Turkey Singapore Singapore Denmark Italy Bangkok 1991 1994 1996 1994 1994 2000 2002 2002 16-65 H. School H. school 6-7 12-15 7-17 20-44 U student 33 Prevalence of Rhinitis in UK Prevalence Age Author Year 35.1% 6-7 Lau et al. 1998 44.0% 13-14 Leung et al. 1997 29.8% 12-18 Leung et al. 1997 49.5% Workers Tong et al. 2001 34 Discussion This study clearly suggests that pollen constitute the most important group of sensitizing allergens in patients with allergic rhinitis in this region with as many as 68.3% of all positive cases sensitized to at least one pollen. In this study IgE - mediated sensitization to fungal allergen was rare in allergic rhinitis patients which means that people in a certain locality had less exposure to mould allergens 35 Pet ownership is not popular in Saudi Arabia and detailed studies on animal dander sensitivity are lacking. Pet ownership is undoubtedly a more common practice in other parts of the non-Moslem world, such as in Europe and America, where more and more people are choosing a solitary existence, accompanied only by a pet animal at home. Allergen calendars could be a helpful guide in determining probable provocative factors among allergic rhinitis patients presenting with a history of sensitization . Spring heralds an epidemiologic peak in the number of cases yearly . 36 Conclusions 1. 2. 3. 4. 5. 6. The results of this study show that even in warm climates pollen , animal dander and HDM allergens may be important sensitizing allergens . Pollens of local horticultural plants are the main sensitizing allergens among patients with allergic rhinitis in the locality studied, which may play a role in the pathogenesis of allergic respiratory diseases and should therefore be considered important factors in the management of patients affected in regions presenting with a generally warm dry climate most of the year . The practice of greening the country seems to contribute to increased rates of allergic sensitization of persons prone to allergic rhinitis. Subtle changes in social practices, like pet ownership, increasing mobilisation and introduction of new potentially allergen. The results of this study are mostly consistent with the results of other studies made in other parts of the world, with some variations due to differences in environmental conditions and social practices . Local environmental and genetic factors are probably involved in the pathogenesis of the disease . 37 Treatment Allergen avoidance * Identification of the responsible allergens * Health education on allergen avoidance Medical treatment * Antihistamines. * Topical corticosteroids. * Anticholinergics. * Decongestants Immunotherapy-injection Sublingual 38 Treatment Symptoms Symptomatic treatments Nasal obstruction due to nonallergic rhinitis * Azelastine HCL nasal spray * Oral decongestant Non-purulent chronic * Increase water intake. post nasal drip * Nasal saline irrigation. * Humidity to bedroom. Bilateral anterior * Intranasal cortisteroid. rhinorrhea * Atrovent spray. * Nasal saline 39