Allergic Rhinitis & Immunotherapy: Hope or Hype

Allergic rhinitis (AR), one of the most familiar complaints seen in primary care, is a common immunologic condition that occurs in genetically predisposed patients. AR is routinely treated through allergen avoidance and pharmacologic therapy. When these measures fail, however, immunologic treatment may be indicated. This review of AR and its treatment focuses on injection and oral immunotherapy.

Congestion; sneezing (particularly paroxysms); itchy nose, palate, and eyes; and runny nose are symptoms characteristic of allergic rhinitis (AR) seen every day in virtually all primary care offices. Patients are plagued not only by their symptoms, but also by AR-related sleep disturbances, resulting in fatigue and daytime sleepiness, irritability, and memory deficits. In children, these sleep disruptions may even cause behavioral disturbances. Depending on the cause, some patients may experience allergic symptoms only with outdoor environmental exposure and subsequent immunoglobulin E (IgE)–mediated responses to otherwise innocuous allergens, while others find that their symptoms are constant, occurring both indoors and out.

Although the prevalence of AR is increasing,¹ allergies are certainly nothing new to humankind. In fact, hieroglyphics and Egyptian wall paintings have been discovered depicting a pharaoh dying from anaphylactic shock after receiving a wasp sting.² In 1565, Leonardo Botallo described AR, calling it “rose catarrh” (mucous or phlegm) or “rose fever,” based on the mistaken idea that the symptoms were caused by rose pollen.² John Babcock, an English physician, first diagnosed an upper respiratory disease that he called “hay fever” in 1819.

Seventy years later, Charles Blackley identified pollen as a cause of hay fever, documenting his findings in his 1873 book Experimental Researches on the Causes and Nature of Catarrhus Aestivus.² Dr. Blackley performed the initial documented attempts at allergy desensitization treatments on himself—a willing patient, as he suffered from AR. He placed rye grass pollen onto his nasal mucosa, finding that after 30 minutes the nostril was completely occluded. He continued his experimentation by repeatedly exposing himself to pollen grains via abraded skin. Alas, he never noted any decrease in his symptoms.³

Presently, AR affects more than 55 million people in the United States⁴—approximately 10% to 30% of the adult population⁵ and more than 40% of children.⁶ The rising prevalence of AR is of concern in older adults, who tend to have related comorbidities (eg, chronic sinusitis, asthma, and otitis media). In fact, AR is the fifth most common chronic disease in the US.⁷

AR and its treatment impose a great economic burden on the health care system, critical in these days of affordable health care. In fact, in 2005 in the US, the overall (direct medical and indirect) cost of AR was $11.2 billion.⁸ Direct costs derive from office visits, diagnostic testing, and therapeutics. Costs are considerably higher when indirect expenses, including decreased productivity, missed school and missed workdays to care for children, and costs of travel to medical appointments, are included. In the US, approximately 3.5 million workdays and 2 million school days are lost each year due to AR.⁹ Decreases in productivity cost an estimated $600 per affected employee per year, all of which results in AR being the fifth costliest chronic disease.^10,11

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