Allergic rhinitis (AR) is the chronic or recurrent IgE-mediated inflammation of the nasal mucosa. 1 It is a burdensome disease affecting patients of all ages. Symptoms vary from nasal itching, sneezing, watery nasal discharge, and nasal congestion. It may be associated with frequent throat clearing, eye itching, tearing, eye redness, palatal itching, and impaired sense of smell and taste.1
Symptoms result from an inflammatory reaction of the nose caused by the interactions of cells and its mediators after exposure to an allergen. More often than not, the patient also suffers from fatigue, irritability, frustration, self-consciousness, and inability to concentrate. These often lead to work absenteeism and an impairment in the quality of life.
AR can be classified by its duration, either as intermittent or persistent, and by the severity of symptoms as mild, moderate, or severe. Intermittent AR is characterized by symptoms occurring less than four days a week or less than four consecutive weeks while persistent AR has symptoms occurring for more than four days a week and for more than four weeks.4
Patients with mild AR have typical symptoms except for sleep disturbances as well as functional impairments in daily activities such as leisure, sports, school, and work. The classification of moderate AR is given to patients who experience one to three of the listed symptoms and a classification of severe AR is given if symptoms are present with night time disturbance and functional impairment.2
According to the 2008 State of the World Allergy Report, an estimated 400 million persons worldwide suffer from AR.10 In Asia, a rising trend in the prevalence of AR and asthma was observed, particularly in low to middle-income countries. Data from the International Study of Asthma and Allergies in Childhood (ISAAC) showed the estimated prevalence of allergic rhinitis among adults in the Asia Pacific region between 10% to 32%.9
In 1996, the Philippines participated in the ISAAC survey and reported 26-32% prevalence of AR among subjects aged 13-14 years.9 During the 6th National Health and Nutrition Survey (NNHeS) in 2003, the prevalence of allergic rhinitis among adults 20 years and above using the ISAAC core questionnaire was 26.8%. However, the survey was conducted only within Metro Manila. Since then, there has been little information regarding the nationwide prevalence of allergic rhinitis in the Philippines.
NNHeS was conducted in 2008 to know the prevalence of leading diseases including atopic diseases. The then estimated overall prevalence of AR in the past 12 months and at any time in the past were 20% and 23.8% respectively.
Currently therapeutic strategy for AR includes patient education, avoidance of allergens and pollutants, pharmacotherapy, and allergen-specific immunotherapy. When choosing pharmacological treatment, the efficacy, safety, cost-effectiveness of drugs, patients’ preferences, disease severity, and the presence of co-morbidities must be assessed.
The pharmacological treatment of AR must include clear recommendations graded into different stages, depending on the level of severity. These treatments usually vary from oral/nasal H1 antihistamines, glucocorticoids, oral/intranasal decongestants, Leukotriene receptor antagonist, and allergic immunotherapy which can be patient-tailored depending on the severity of the symptoms.
Recent advancement and emerging AR management include specific allergen immunotherapy (AIT), through subcutaneous or oral (sublingual) administration. It is highly effective for treating AR caused by pollen and house dust mites (HDM) in adults and children. A correct allergological diagnosis is required for its indication. It can alter the natural course of allergic respiratory disease, reducing the frequency of asthma episodes and preventing new sensitizations
A number of systematic reviews (SRs) of subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT) (or both) for AR have been conducted. A committee of the European Academy of Allergy and Clinical Immunology critically assessed these SRs for evidence of the effectiveness, safety, and cost-effectiveness of allergen immunotherapy for allergic rhinoconjunctivitis (ARC). These SRs suggested that, in carefully selected patients, SCIT and SLIT resulted in significant reductions in symptom scores and medication requirements for ARC with reassuring safety data.8
The major recent development in AIT in the US for ARC has been the introduction of SLIT tablets containing Timothy grass, a five-grass mixture, short ragweed, or HDM (Dermatophagoides pteronyssinus and farinae) extracts. In most, a dose-ranging study has been performed that identified an effective dose as well as one or more less effective doses.In the case of ragweed and HDMs, there were also studies that suggested that doses higher than those eventually approved carried safety concerns.7
Use of SLIT with liquid preparations in the US has been limited by the lack of an FDA-approved allergen extract for SLIT, although there is some “off label” use. In Europe, SLIT with liquid preparations is widely employed. However, studies of extracts from three major European manufacturers suggested widely varying doses, some of which are well below those that have proven to be necessary for clinical efficacy in dose-ranging studies of SLIT tablets.6,12
AR can be a very troublesome condition, affecting primarily the quality of life of the patients as well as their productivity at work. It can be classified as seasonal or perennial, which has the attraction of directing attention to the relevant aeroallergen, or as intermittent and persistent, and mild or moderate/severe that reflects more the burden of the disease on the patient.5
Treatment can be modified depending on the severity of symptoms of the patient. Emerging therapy for AR is allergen immunotherapy which are now validated by recent studies as highly effective. Previously, AR was considered to be a trivial condition. However, its impact on the socio-economic aspect as well as on the quality of life of patients has been recognized in clinical studies.
Knowing the trends in the prevalence of allergic diseases can assist in drafting health policies and plans in improving access to medical care and in achieving better control of symptoms, eventually improving the quality of life of the patients.
 Caro R, Acuin J, Villegas M, Llanes EG, Calaquian C, Dumlao KJ. Clinical Practice Guidelines, Allergic Rhinitis in Adults (December 2016). Philippine Society of Otolaryngology- Head and Neck Surgery 2016. 24-30
 Classification of AR according to the ARIA document (modified by Valero). J InvestigAllergol Clin Immunol 2010; Vol. 20, Suppl. 1: 37-42
 Cua-Lim F, Roa C Jr, Ferreria M, Sumpaico M, Tuazon A, Amores JP, Cue PE, Cruzat L, Castillo-Carandang N. Prevalence of asthma in Metro Manila, Philippines. Philipp J Allergy Immunol 1997;4:9-20.
 Fokkens WJ, Lund VI, Mullol J, Bachert C, Alobid I, BaroodyFuad, et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2012. Rhinology. 2012; 50(Supplement 23).
 Hoyte FC, Nelson H. Recent Advances in Allergic Rhinitis. F1000Research 2018, 7(F1000 Faculty Rev):1333 Last updated: 23 AUG 2018
 Larenas-Linnemann DE, Mosges R: Dosing of European sublingual immunotherapy maintenance solutions relative to monthly recommended dosing of subcutaneous immunotherapy.Allergy Asthma Proc. 2016; 37(1): 50–6.
 Nayak AS, Atiee GJ, Dige E, et al.:Safety of ragweed sublingual allergy immunotherapy tablets in adults with allergic rhinoconjunctivitis. Allergy Asthma Proc.2012; 33(5): 404–10.
 Nurmatov U, Dhami S, Arasi S, et al.: Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic overview of systematic reviews. Clin Transl Allergy. 2017; 7: 24.
 The International Study of Asthma and Allergies in Childhood (ISAAC) Steering Committee. Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC. Lancet 1998;351:1225-32.
 Pawankar R, Cagnani CE, Bousquet J, Canonica GW, Cruz AA, KalinerMA, Lanier BQ. State of world allergy report 2008: allergy and chronicrespiratory diseases. World Allergy Organiz J 2008;1 Suppl 1:S4-17.
 Wallace DV, Dykewicz MS, Bernstein DI, Blessing-Moore J, Cox L, KhanDA, Lang DM, Nicklas RA, Oppenheimer J, Portnoy JM, RandolphCC, Schuller D, Spector SL, Tilles SA. The diagnosis and managementof rhinitis: an updated practice parameter. J Allergy Clin Immunol2008;122:S1-84.
 Tucker MH, Tankersley MS, ACAAI Immunotherapy and Diagnostics Committee: Perception and practice of sublingual immunotherapy among practicing allergists. Ann Allergy Asthma Immunol.2008; 101(4): 419–25.