Decreased Prevalence of Allergic Rhinitis, Asthma and Eczema in Riyadh City, Saudi Arabia

MATERIALS AND METHODS

The present study was conducted during the year 2007-09 using a multistage, stratified, random-sampling technique, by recruiting 1,100 school-age children=s aged 6-14 years, which comprised of 815 boys and 285 girls belonging to middle and upper socioeconomic class. The subjects include Saudi male and female students studying in at different schools in Riyadh City, Saudi Arabia. These schools are divided into three educational levels (primary, intermediate and secondary); the age group included in this study falls below secondary levels. Phase 1 model questionnaire of International Study of Asthma and Allergies in Childhood (ISAAC) along with a letter of explanation were distributed and asked to be filled and returned back by parents of these children, who are Saudi nationals by birth and living in Riyadh from past 25 years. Interviews with help of a qualified trained nurse were taken with the parents who are illiterate. Questions related previous history, diagnosis, age at diagnosis and treatment were asked for the identification of asthma among children. Allergic rhinitis was diagnosed by enquiring with questions such as history of sneezing or blocked nose during the last 6 months when he/she did not have a cold or flu and has your child ever had hay fever? Questions concerning the diagnosis of eczema were as follows: has your child ever had an recurrent itchy rash for at least months and has your child ever had eczema? Food and drug allergies were identified with questions such as the observed symptoms in your child after food ingestion, if any and the kind of food? In your opinion, does your child have a drug allergy? etc. The questionnaire also included the diagnosis of similar conditions among parents and first-degree relatives. Our institutional ethics committee has approved the present study. A signed consent from parents and children=s assent was obtained from each subject after explaining the nature of study. Data from all the questionnaires were properly entered in MS-excel spread sheets and was analyzed.

RESULTS AND DISCUSSION

Total prevalence rates for allergic rhinitis, asthma, eczema, food and drug allergies among the studied children were noted to be 12.7, 11.4, 5.6, 1.75 and 0.27%, respectively. Present results demonstrate that Allergic rhinitis is the most common allergic disorders among Saudi children with a frequency of 12.7%; however a previous study conducted in 1996 reported its prevalence as 25% (p<0.05). This significant decrease or variation could be due to reduced exposure of children to intrinsic and/or extrinsic allergens or variation in geographical regions and their climates. This factor could be further supported by the fact that both parents and children showed the similar prevalence rate for allergic rhinitis (12.6 and 12.7%), respectively indicating the exposure to similar allergens. A total of 27.82% of children are allergically sensitive, out of which 85.94% of them showed one type of allergy, whereas the remaining 14.05% were sensitive to more than one type of allergies. Among the different allergies noted in sensitive children, allergic rhinitis, asthma and atopic dermatitis are found to be more prevalent as compared to food and drug allergies. Out of 2343 parents, total prevalence rate of allergic rhinitis is 12.6%, asthma is 3.9%, eczema is 7.72%, food allergy is 0.28% and drug allergy is 0.43%. Allergic sensitivity among parents of studied children was reported as 20.9%, out of them 94.91% were reported to be sensitive to one type of allergy, whereas 5.08% were sensitive to more than one type of allergies. Though, the prevalence rate of Allergic rhinitis in Saudi children as demonstrated is not as high as seen in children of other gulf countries such as Qatar (30.5%), UAE (22.9%), Lebanon (21.2%) and Iran (23.6%), but it is close to the children of Oman (7.4-10.5%) (22-27).

A total of 749 out of 3383 siblings (22.1%), also reported as sensitive to different allergies, out of which 95.99% were sensitive to one type of allergy, whereas 4% were sensitive to more than one type of allergy. Total prevalence rates for allergic rhinitis, asthma, eczema and food and drug allergy among siblings were 9.1, 8, 5.7, 0.40 and 0.38%, respectively (Fig. 1). Allergic rhinitis, asthma, eczema are reported to be dominantly prevalent in both parents and siblings of affected children.

Prevalence of childhood asthma in Saudi Arabia was reported to be increased from 8 to 23% in between 1985-2001 and present results demonstrated the significant reduction in its prevalence i.e., 11.4% in children , while the prevalence rates in siblings and family members were 9.1 and 8.56%, respectively. Asthma prevalence rate as observed in the current study is similar to other studies from Middle Eastern countries, which have also reported its high prevalence among school aged children; wherein it was reported to be 10.5-20% in Oman, 19.8% in Qatar, 16.8% in Kuwait, 14.5% in Iran, 13.6% in UAE and 4.8% in Lebanon (Bener et al., 1994; Al-Riyami et al., 2003; Janahi et al., 2006; Waked and Salameh, 2008). Reduction in the prevalence of both childhood Asthma and Allergic Rhinitis in the last decade could be particularly interesting to clinicians and epidemiologists in identification of risk factors and treatment. The variations in the results of asthma prevalence studies from different countries may be effected not only by the applied protocol, but also by demographic and ethnic, geo-graphic and socioeconomic differences in the study populations.

Fig. 1:	The distribution the allergy disorders among the study subjects

Eczema formed the third most prevalent allergic disorder among the school children with 5.6% and in siblings it was 5.5%. A 3.6% prevalence rate was found in fathers, while it was 7.7% among mothers but combined prevalence ranged up to 6.2% which includes both children and their family members. Robertson et al. (1991) reported the prevalence of eczema to be 8.7% in Jeddah, second major metropolitan city in Saudi Arabia, while Al-Frayh et al. (2001) reported it to be in between 12-13%, which is significantly different from our study results. In UAE, eczema was found to be 8.8% in mothers vs. 10.4% in fathers. Other studies have reported that the prevalence of childhood eczema to be 22.5% in Qatar, 11.8% in Lebanon, 7.5-14.4% in Oman, 10.6% in Iran. Present results indicate that Saudi children are comparatively less prone to eczema as compared to other Gulf countries. Among Swedish children, eczema was found to be doubled from 7.05 to 18.28% during 1972-1991 (Dubois et al., 1998), indicating the time associated variations in the prevalence rates of eczema, which could be mostly due to altered environment and/or exposure of different allergens. Food and drug allergies were found least common in children with 1.75 and 0.27%, respectively, while in family members their prevalence rates are 0.35 and 0.38%, respectively hence carry little or no significance.

This cross sectional study highlights the current trend of allergic diseases among school children in Riyadh City, which includes immigrants from all over the kingdom. Study results obtained from this study could also help to set up a base reference for further epidemiological studies in other metropolitan cities of this country. The results can be used for planning methods and means of prevention, education and better planning management of allergy through public health and school programs.

CONCLUSION

We found that allergic rhinitis (12.7%) is most common allergic disorder followed by bronchial asthma (11.4%), eczema (5.6%) in children indicating their significant reduction in prevalence rates as compared to earlier studies in this region. Food and drug allergies (1.75 and 0.27%) were least common in children and non significant. Periodic studies in different regions of this country will be helpful to obtain a more reliable concept of the prevalence of allergic disorders in Saudi children.

ACKNOWLEDGMENTS

Authors convey their sincere thanks to school managements, children and their parents who participated in this study. Authors deeply appreciate Dr. Noor Ahmad Shaik for proof reading and also for his valuable comments to improve this article.