Allergic Rhinitis
- Author: Javed Sheikh, MD; Chief Editor: Michael A Kaliner, MD
Practice Essentials
Rhinitis, which occurs most commonly as allergic rhinitis, is an inflammation of the nasal membranes that is characterized by sneezing, nasal congestion, nasal itching, and rhinorrhea, in any combination.[2] Although allergic rhinitis itself is not life-threatening (unless accompanied by severe asthma or anaphylaxis), morbidity from the condition can be significant.
Essential update: FDA approves second sublingual immunotherapy for allergic rhinitis
The FDA approved a second SL immunotherapy for Timothy grass (Grastek) in April 2014 for adults and children aged 5 years or older. Once-daily Oralair was the first SL immunotherapy approved for use in patients aged 10-65 years.
Grastek is the first sublingual allergy immunotherapy approved for patients as young as 5 and should be initiated at least 12 weeks before the start of the grass pollen season. Efficacy and safety in North America was established in a large study (n=1500) of adults and children aged 5-65 years. Results showed a 23% improvement of symptoms in the entire grass pollen season.[7, 8, 9]
Signs and Symptoms
History
Signs and symptoms of allergic rhinitis include the following:
- Sneezing
- Itching: Nose, eyes, ears, palate
- Rhinorrhea
- Postnasal drip
- Congestion
- Anosmia
- Headache
- Earache
- Tearing
- Red eyes
- Eye swelling
- Fatigue
- Drowsiness
- Malaise
Complications of this allergic rhinitis include the following:
- Acute or chronic sinusitis
- Otitis media
- Sleep disturbance or apnea
- Dental problems (overbite): Caused by excessive breathing through the mouth
- Palatal abnormalities
- Eustachian tube dysfunction
Physical examination
Nasal features of allergic rhinitis can include the following:
- Nasal crease: A horizontal crease across the lower half of the bridge of the nose; caused by repeated upward rubbing of the tip of the nose by the palm of the hand
- Thin, watery nasal secretions
- Deviation or perforation of the nasal septum: May be associated with chronic rhinitis, although there can be other, unrelated causes
Manifestations of allergic rhinitis affecting the ears, eyes, and oropharynx include the following:
- Ears: Retraction and abnormal flexibility of the tympanic membrane
- Eyes: Injection and swelling of the palpebral conjunctivae, with excess tear production; Dennie-Morgan lines (prominent creases below the inferior eyelid); and dark circles around the eyes (“allergic shiners”), which are related to vasodilation or nasal congestion
- Oropharynx: "Cobblestoning," that is, streaks of lymphoid tissue on the posterior pharynx; tonsillar hypertrophy; and malocclusion (overbite) and a high-arched palate
Diagnosis
Laboratory tests used in the diagnosis of allergic rhinitis include the following:
- Allergy skin tests (immediate hypersensitivity testing): An in vivo method of determining immediate (IgE-mediated) hypersensitivity to specific allergens
- Radioallergosorbent test (RAST): Indirectly measures the quantity of immunoglobulin E (IgE) serving as an antibody to a particular antigen
- Total serum IgE: Neither sensitive nor specific for allergic rhinitis, but the results can be helpful in some cases when combined with other factors
- Total blood eosinophil count: Neither sensitive nor specific for the diagnosis, but, as with total serum IgE, can sometimes be helpful when combined with other factors
Imaging studies used in the diagnosis and evaluation of allergic rhinitis include the following:
- Radiography: Can be helpful for evaluating possible structural abnormalities or to help detect complications or comorbid conditions, such as sinusitis or adenoid hypertrophy
- Computed tomography scanning: Can be very helpful for evaluating acute or chronic sinusitis
- Magnetic resonance imaging: Also can be helpful for evaluating sinusitis
Management
The management of allergic rhinitis consists of the following 3 major treatment strategies:
- Environmental control measures and allergen avoidance: These include keeping exposure to allergens such as pollen, dust mites, and mold to a minimum
- Pharmacologic management: Patients are often successfully treated with oral antihistamines, decongestants, or both; regular use of an intranasal steroid spray may be more appropriate for patients with chronic symptoms
- Immunotherapy: This treatment may be considered more strongly with severe disease, poor response to other management options, and the presence of comorbid conditions or complications; immunotherapy is often combined with pharmacotherapy and environmental control
Background
Rhinitis is defined as inflammation of the nasal membranes[1] and is characterized by a symptom complex that consists of any combination of the following: sneezing, nasal congestion, nasal itching, and rhinorrhea.[2] The eyes, ears, sinuses, and throat can also be involved. Allergic rhinitis is the most common cause of rhinitis. It is an extremely common condition, affecting approximately 20% of the population.
Although allergic rhinitis is not a life-threatening condition, complications can occur and the condition can significantly impair quality of life,[3, 4] which leads to a number of indirect costs. The total direct and indirect cost of allergic rhinitis was recently estimated to be $5.3 billion per year.[5] A 2011 analysis determined that patients with allergic rhinitis averaged 3 additional office visits, 9 more prescriptions filled, and $1500 in incremental healthcare costs in 1 year than similar patients without allergic rhinitis.[6]
Pathophysiology
Allergic rhinitis involves inflammation of the mucous membranes of the nose, eyes, eustachian tubes, middle ear, sinuses, and pharynx. The nose invariably is involved, and the other organs are affected in certain individuals. Inflammation of the mucous membranes is characterized by a complex interaction of inflammatory mediators but ultimately is triggered by an immunoglobulin E (IgE)–mediated response to an extrinsic protein.[10]
The tendency to develop allergic, or IgE-mediated, reactions to extrinsic allergens (proteins capable of causing an allergic reaction) has a genetic component. In susceptible individuals, exposure to certain foreign proteins leads to allergic sensitization, which is characterized by the production of specific IgE directed against these proteins. This specific IgE coats the surface of mast cells, which are present in the nasal mucosa. When the specific protein (eg, a specific pollen grain) is inhaled into the nose, it can bind to the IgE on the mast cells, leading to immediate and delayed release of a number of mediators.[10, 11, 12]
The mediators that are immediately released include histamine, tryptase, chymase, kinins, and heparin.[11, 12] The mast cells quickly synthesize other mediators, including leukotrienes and prostaglandin D2.[13, 14, 15] These mediators, via various interactions, ultimately lead to the symptoms of rhinorrhea (ie, nasal congestion, sneezing, itching, redness, tearing, swelling, ear pressure, postnasal drip). Mucous glands are stimulated, leading to increased secretions. Vascular permeability is increased, leading to plasma exudation. Vasodilation occurs, leading to congestion and pressure. Sensory nerves are stimulated, leading to sneezing and itching. All of these events can occur in minutes; hence, this reaction is called the early, or immediate, phase of the reaction.
Over 4-8 hours, these mediators, through a complex interplay of events, lead to the recruitment of other inflammatory cells to the mucosa, such as neutrophils, eosinophils, lymphocytes, and macrophages.[16] This results in continued inflammation, termed the late-phase response. The symptoms of the late-phase response are similar to those of the early phase, but less sneezing and itching and more congestion and mucus production tend to occur.[16] The late phase may persist for hours or days.
Systemic effects, including fatigue, sleepiness, and malaise, can occur from the inflammatory response. These symptoms often contribute to impaired quality of life.
Epidemiology
Frequency
United States
Allergic rhinitis affects approximately 40 million people in the United States.[17]Recent US figures suggest a 20% cumulative prevalence rate.[18, 19]
International
Scandinavian studies have demonstrated a cumulative prevalence rate of 15% in men and 14% in women.[20] The prevalence of allergic rhinitis may vary within and among countries.[21, 22, 23, 24] This may be due to geographic differences in the types and potency of different allergens and the overall aeroallergen burden.
Mortality/Morbidity
While allergic rhinitis itself is not life-threatening (unless accompanied by severe asthma or anaphylaxis), morbidity from the condition can be significant. Allergic rhinitis often coexists with other disorders, such as asthma, and may be associated with asthma exacerbations.[25, 26, 27]
Allergic rhinitis is also associated with otitis media, eustachian tube dysfunction,sinusitis, nasal polyps, allergic conjunctivitis, and atopic dermatitis.[1, 2, 28] It may also contribute to learning difficulties, sleep disorders, and fatigue.[29, 30, 31]
- Numerous complications that can lead to increased morbidity or even mortality can occur secondary to allergic rhinitis. Possible complications include otitis media, eustachian tube dysfunction, acute sinusitis, and chronic sinusitis.
- Allergic rhinitis can be associated with a number of comorbid conditions, including asthma, atopic dermatitis, and nasal polyps. Evidence now suggests that uncontrolled allergic rhinitis can actually worsen the inflammation associated with asthma[25, 26, 27] or atopic dermatitis.[28] This could lead to further morbidity and even mortality.
- Allergic rhinitis can frequently lead to significant impairment of quality of life. Symptoms such as fatigue, drowsiness (due to the disease or to medications), and malaise can lead to impaired work and school performance, missed school or work days, and traffic accidents. The overall cost (direct and indirect) of allergic rhinitis was recently estimated to be $5.3 billion per year.[5]
Race
Allergic rhinitis occurs in persons of all races. Prevalence of allergic rhinitis seems to vary among different populations and cultures, which may be due to genetic differences, geographic factors or environmental differences, or other population-based factors.
Sex
In childhood, allergic rhinitis is more common in boys than in girls, but in adulthood, the prevalence is approximately equal between men and women.
Age
Onset of allergic rhinitis is common in childhood, adolescence, and early adult years, with a mean age of onset 8-11 years, but allergic rhinitis may occur in persons of any age. In 80% of cases, allergic rhinitis develops by age 20 years.[32]The prevalence of allergic rhinitis has been reported to be as high as 40% in children, subsequently decreasing with age.[18, 19] In the geriatric population, rhinitis is less commonly allergic in nature
DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are il
