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Allergic rhinitis

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Title: Allergic rhinitis Author: PAM Klinika Otolaryngologii Last modified by: Magnus Created Date: 4/18/2005 12:30:49 AM Document presentation format – PowerPoint PPT presentation

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Title: Allergic rhinitis


1
Allergic rhinitis
2
  • Rhinitis is defined as inflammation of the nasal
    membranes and is characterized by a symptom
    complex that consists of any combination of the
    following sneezing, nasal congestion, nasal
    itching, and rhinorrhea.
  • The eyes, ears, sinuses, and throat can also be
    involved.
  • Allergic rhinitis is very common cause of
    rhinitis.

3
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.

4
  • 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.

5
  • The mediators that are immediately released
    include histamine, tryptase, chymase, kinins, and
    heparin.
  • The mast cells quickly synthesize other
    mediators, including leukotrienes and
    prostaglandin D2.
  • 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.

6
  • 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.
  • 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.
  • The late phase may persist for hours or days.

7
  •          A number of 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 or atopic dermatitis. 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.

8
History
  • Symptoms and chronicity
  • Trigger factors
  • Response to treatment
  • Comorbid conditions
  • Family history
  • Environmental and occupational exposure
  • Effects on quality of life

9
Symptoms and chronicity
  • Determine the age of onset of symptoms and
    whether symptoms have been present continuously
    since onset. While the onset of allergic rhinitis
    can occur well into adulthood, most patients
    develop symptoms by age 20 years.
  • Determine the time pattern of symptoms and
    whether symptoms occur at a consistent level
    throughout the year (ie, perennial rhinitis),
    only occur in specific seasons (ie, seasonal
    rhinitis), or a combination of the two. During
    periods of exacerbation, determine whether
    symptoms occur on a daily basis or only on an
    episodic basis. Determine whether the symptoms
    are present all day or only at specific times
    during the day.
  • Determine which organ systems are affected and
    the specific symptoms. Some patients have
    exclusive involvement of the nose, while others
    have involvement of multiple organs. Some
    patients primarily have sneezing, itching,
    tearing, and watery rhinorrhea (the classic
    hayfever presentation), while others may only
    complain of congestion. Significant complaints of
    congestion, particularly if unilateral, might
    suggest the possibility of structural
    obstruction, such as a polyp, foreign body, or
    deviated septum.

10
Trigger factors
  • o        Determine whether symptoms are related
    temporally to specific trigger factors. This
    might include exposure to pollens outdoors, mold
    spores while doing yard work, specific animals,
    or dust while cleaning the house.
  • o        Irritant triggers such as smoke,
    pollution, and strong smells can aggravate
    symptoms in a patient with allergic rhinitis.
    These are also common triggers of vasomotor
    rhinitis. Many patients have both allergic
    rhinitis and vasomotor rhinitis.
  • o        Other patients may describe year-round
    symptoms that do not appear to be associated with
    specific triggers. This could be consistent with
    nonallergic rhinitis, but perennial allergens,
    such as dust mite or animal exposure, should also
    be considered in this situation. With chronic
    exposure and chronic symptoms, the patient may
    not be able to associate symptoms with a
    particular trigger.

11
Response to treatment
  • o        Response to treatment with
    antihistamines supports the diagnosis of allergic
    rhinitis, although sneezing, itching, and
    rhinorrhea associated with nonallergic rhinitis
    can also improve with antihistamines.
  • o        Response to intranasal corticosteroids
    supports the diagnosis of allergic rhinitis,
    although some cases of nonallergic rhinitis
    (particularly the nonallergic rhinitis with
    eosinophils syndrome NARES) also improve with
    nasal steroids.

12
Comorbid conditions
  • o        Patients with allergic rhinitis may have
    other atopic conditions such as asthma or atopic
    dermatitis. Of patients with allergic rhinitis,
    20 also have symptoms of asthma. Uncontrolled
    allergic rhinitis may cause worsening of asthma
    or even atopic dermatitis. Explore this
    possibility when obtaining the patient history.
  • o        Look for conditions that can occur as
    complications of allergic rhinitis. Sinusitis
    occurs quite frequently. Other possible
    complications include otitis media, sleep
    disturbance or apnea, dental problems (overbite),
    and palatal abnormalities. The treatment plan
    might be different if one of these complications
    is present. Nasal polyps occur in association
    with allergic rhinitis, although whether allergic
    rhinitis actually causes polyps remains unclear.
    Polyps may not respond to medical treatment and
    might predispose a patient to sinusitis or sleep
    disturbance (due to congestion).
  • o        Investigate past medical history,
    including other current medical conditions.
    Diseases such as hypothyroidism or sarcoidosis
    can cause nonallergic rhinitis. Concomitant
    medical conditions might influence the choice of
    medication.

13
Family history
  • o        Because allergic rhinitis has a
    significant genetic component, a positive family
    history for atopy makes the diagnosis more
    likely.
  • o        In fact, a greater risk of allergic
    rhinitis exists if both parents are atopic than
    if one parent is atopic. However, the cause of
    allergic rhinitis appears to be multifactorial,
    and a person with no family history of allergic
    rhinitis can develop allergic rhinitis.

14
Environmental and occupational exposure
  • o        A thorough history of environmental
    exposures helps to identify specific allergic
    triggers. This should include investigation of
    risk factors for exposure to perennial allergens
    (eg, dust mites, mold, pets). Risk factors for
    dust mite exposure include carpeting, heat,
    humidity, and bedding that does not have dust
    miteproof covers. Chronic dampness in the home
    is a risk factor for mold exposure. A history of
    hobbies and recreational activities helps
    determine risk and a time pattern of pollen
    exposure.
  • o        Ask about the environment of the
    workplace or school. This might include exposure
    to ordinary perennial allergens (eg, mites, mold,
    pet dander) or unique occupational allergens (eg,
    laboratory animals, animal products, grains and
    organic materials, wood dust, latex, enzymes).

15
Effects on quality of life
  • o        An accurate assessment of the morbidity
    of allergic rhinitis cannot be obtained without
    asking about the effects on the patient's quality
    of life. Specific validated questionnaires are
    available to help determine effects on quality of
    life.
  • o        Determine the presence of symptoms such
    as fatigue, malaise, drowsiness (which may or may
    not be related to medication), and headache.
  • o        Investigate sleep quality and ability to
    function at work.

16
Physical
  • The physical examination should focus on the
    nose, but examination of facial features, eyes,
    ears, oropharynx, neck, lungs, and skin is also
    important. Look for physical findings that may be
    consistent with a systemic disease that is
    associated with rhinitis.

17
Physical
  •          General facial features
  •          Nose
  •          Ears, eyes, and oropharynx
  •          Neck
  •          Lungs
  •          Skin
  •          Other

18
Nose
  • The nasal examination is best accomplished with
    a nasal speculum or an otoscope with nasal
    adapter. In the specialist's office, a rigid or
    flexible rhinolaryngoscope may be used.
  • The mucosa of the nasal turbinates may be
    swollen (boggy) and have a pale, bluish-gray
    color. Some patients may have predominant
    erythema of the mucosa, which can also be
    observed with rhinitis medicamentosa, infection,
    or vasomotor rhinitis. While pale, boggy,
    blue-gray mucosa is typical for allergic
    rhinitis, mucosal examination findings cannot
    definitively distinguish between allergic and
    nonallergic causes of rhinitis.
  • Assess the character and quantity of nasal
    mucus. Thin and watery secretions are frequently
    associated with allergic rhinitis, while thick
    and purulent secretions are usually associated
    with sinusitis however, thicker, purulent,
    colored mucus can also occur with allergic
    rhinitis.
  • Examine the nasal septum to look for any
    deviation or septal perforation, which may be
    present due to chronic rhinitis, granulomatous
    disease, cocaine abuse, prior surgery, topical
    decongestant abuse, or, rarely, topical steroid
    overuse.
  • Examine the nasal cavity for other masses such
    as polyps or tumors. Polyps are firm gray masses
    that are often attached by a stalk, which may not
    be visible. After spraying a topical
    decongestant, polyps do not shrink, while the
    surrounding nasal mucosa does shrink.

19
Ears, eyes, and oropharynx
  • o        Perform otoscopy to look for tympanic
    membrane retraction, air-fluid levels, or
    bubbles. Performing pneumatic otoscopy can be
    considered to look for abnormal tympanic membrane
    mobility. These findings can be associated with
    allergic rhinitis, particularly if eustachian
    tube dysfunction or secondary otitis media is
    present.
  • o        Ocular examination may reveal findings
    of injection and swelling of the palpebral
    conjunctivae, with excess tear production.
    Dennie-Morgan lines (prominent creases below the
    inferior eyelid) are associated with allergic
    rhinitis.
  • o        The term cobblestoning" is used to
    describe streaks of lymphoid tissue on the
    posterior pharynx, which is commonly observed
    with allergic rhinitis. Tonsillar hypertrophy can
    also be observed. Malocclusion (overbite) and a
    high-arched palate can be observed in patients
    who breathe from their mouths excessively.

20
  •          Neck Look for evidence of
    lymphadenopathy or thyroid disease.
  •          Lungs Look for the characteristic
    findings of asthma.
  •          Skin Evaluate for possible atopic
    dermatitis.
  •          Other Look for any evidence of
    systemic diseases that may cause rhinitis (eg,
    sarcoidosis, hypothyroidism, immunodeficiency,
    ciliary dyskinesia syndrome, other connective
    tissue diseases).

21
Causes
  • The causes of allergic rhinitis may differ
    depending on whether the symptoms are seasonal,
    perennial, or sporadic/episodic. Some patients
    are sensitive to multiple allergens and can have
    perennial allergic rhinitis with seasonal
    exacerbations. While food allergy can cause
    rhinitis, particularly in children, it is rarely
    a cause of allergic rhinitis in the absence of
    gastrointestinal or skin symptoms.

22
Pollens (tree, grass, and weed)
  •         Tree pollens, which vary by geographic
    location, are typically present in high counts
    during the spring, although some species produce
    their pollens in the fall. Common tree families
    associated with allergic rhinitis include birch,
    oak, maple, cedar, olive, and elm.
  •         Grass pollens also vary by geographic
    location. Most of the common grass species are
    associated with allergic rhinitis, including
    Kentucky bluegrass, orchard, redtop, timothy,
    vernal, meadow fescue, Bermuda, and perennial
    rye. A number of these grasses are
    cross-reactive, meaning that they have similar
    antigenic structures (ie, proteins recognized by
    specific IgE in allergic sensitization).
    Consequently, a person who is allergic to one
    species is also likely to be sensitive to a
    number of other species. The grass pollens are
    most prominent from the late spring through the
    fall but can be present year-round in warmer
    climates.
  •         Weed pollens also vary geographically.
    Many of the weeds, such as short ragweed, which
    is a common cause of allergic rhinitis in much of
    the United States, are most prominent in the late
    summer and fall. Other weed pollens are present
    year-round, particularly in warmer climates.
    Common weeds associated with allergic rhinitis
    include short ragweed, western ragweed, pigweed,
    sage, mugwort, yellowdock, sheep sorrel, English
    plantain, lamb's quarters, and Russian thistle.

23
Outdoor molds
  • Atmospheric conditions can affect the growth and
    dispersion of a number of molds therefore, their
    airborne prevalence may vary depending on climate
    and season.
  • For example, Alternaria and Cladosporium are
    particularly prevalent in the dry and windy
    conditions of the Great Plains states, where they
    grow on grasses and grains. Their dispersion
    often peaks on sunny afternoons. They are
    virtually absent when snow is on the ground in
    winter, and they peak in the summer months and
    early fall.
  • Aspergillus and Penicillium can be found both
    outdoors and indoors (particularly in humid
    households), with variable growth depending on
    the season or climate. Their spores can also be
    dispersed in dry conditions.
  • Perennial allergic rhinitis is typically caused
    by allergens within the home but can also be
    caused by outdoor allergens that are present
    year-round. In warmer climates, grass pollens can
    be present throughout the year. In some climates,
    individuals may be symptomatic due to trees and
    grasses in the warmer months and molds and weeds
    in the winter.

24
House dust mites
  •   2 major house dust mite species are associated
    with allergic rhinitis. These are
    Dermatophagoides farinae and Dermatophagoides
    pteronyssinus.
  • These mites feed on organic material in
    households, particularly the skin that is shed
    from humans and pets. They can be found in
    carpets, upholstered furniture, pillows,
    mattresses, comforters, and stuffed toys.
  • While they thrive in warmer temperatures and
    high humidity, they can be found year-round in
    many households. On the other hand, dust mites
    are rare in arid climates.

25
Pets
  • Allergy to indoor pets is a common cause of
    perennial allergic rhinitis.
  • Cat and dog allergies are encountered most
    commonly in allergy practice, although allergy
    has been reported to occur with most of the furry
    animals and birds that are kept as indoor pets.

26
  • o        Cockroaches While cockroach allergy is
    most frequently considered a cause of asthma,
    particularly in the inner city, it can also cause
    perennial allergic rhinitis in infested
    households.
  • o        Rodents Rodent infestation may be
    associated with allergic sensitization.

27
Sporadic allergic rhinitis
  •         Intermittent brief episodes of allergic
    rhinitis, is caused by intermittent exposure to
    an allergen. Often, this is due to pets or
    animals to which a person is not usually exposed.
    Sporadic allergic rhinitis can also be due to
    pollens, molds, or indoor allergens to which a
    person is not usually exposed. While allergy to
    specific foods can cause rhinitis, an individual
    affected by food allergy also usually has some
    combination of gastrointestinal, skin, and lung
    involvement. In this situation, the history
    findings usually suggest an association with a
    particular food. Watery rhinorrhea occurring
    shortly after eating may be vasomotor (and not
    allergic) in nature, mediated via the vagus nerve
    (This often is called gustatory rhinitis.).

28
Occupational allergic rhinitis
  •          is caused by exposure to allergens in
    the workplace, can be sporadic, seasonal, or
    perennial. People who work near animals (eg,
    veterinarians, laboratory researchers, farm
    workers) might have episodic symptoms when
    exposed to certain animals, daily symptoms while
    at the workplace, or even continual symptoms
    (which can persist in the evenings and weekends
    with severe sensitivity due to persistent
    late-phase inflammation). Some workers who may
    have seasonal symptoms include farmers,
    agricultural workers (exposure to pollens,
    animals, mold spores, and grains), and other
    outdoor workers. Other significant occupational
    allergens that may cause allergic rhinitis
    include wood dust, latex (due to inhalation of
    powder from gloves), acid anhydrides, glues, and
    psyllium (eg, nursing home workers who administer
    it as medication).

29
Problems to be Considered
  • Vasomotor rhinitisGustatory rhinitis (vagally
    mediated)Rhinitis medicamentosa (eg, due to
    topical decongestants, antihypertensives, cocaine
    abuse)Hormonal rhinitis (eg, related to
    pregnancy, hypothyroidism, oral contraceptive
    use)Anatomic rhinitis (eg, deviated septum,
    choanal atresia, adenoid hypertrophy, foreign
    body, nasal tumor)NARES Immotile cilia syndrome
    (ciliary dyskinesis)Cerebrospinal fluid
    leakNasal polypsGranulomatous rhinitis (eg,
    Wegener granulomatosis, sarcoidosis)

30
Lab Studies
  • Allergy skin tests
  • In vitro allergy tests, (RAST)
  • Testing every patient for sensitivity to every
    allergen known is not practical. Therefore,
    select a limited number of allergens for testing
    (this applies to both skin testing and RAST).
    When selecting allergens, select from among the
    allergens that are present locally and are known
    to cause clinically significant allergic disease.
    A clinician who is specifically trained in
    allergy testing should select allergens for
    testing.
  • Total serum IgE
  • Total blood eosinophil count

31
Imaging Studies
  • Radiography
  • Sinus films
  • Neck films
  • CT scanning
  • MRI

32
  •          CT scanning Coronal CT scan images of
    the sinuses can be very helpful for evaluating
    acute or chronic sinusitis. In particular,
    obstruction of the osteomeatal complex (a
    confluence of drainage channels from the sinuses)
    can be seen quite clearly. CT scanning may also
    help delineate polyps, turbinate swelling, septal
    abnormalities (eg, deviation), and bony
    abnormalities (eg, concha bullosa).
  •          MRI For evaluating sinusitis, MRI
    images are generally less helpful than CT scan
    images, largely because the bony structures are
    not seen as clearly on MRI images. However, soft
    tissues are visualized quite well, making MRI
    images helpful for diagnosing malignancies of the
    upper airway.

33
Nasal cytology
  • A nasal smear can sometimes be helpful for
    establishing the diagnosis of allergic rhinitis.
    A sample of secretions and cells is scraped from
    the surface of the nasal mucosa using a special
    sampling probe. Secretions that are blown from
    the nose are not adequate. The presence of
    eosinophils is consistent with allergic rhinitis
    but also can be observed with NARES. Results are
    neither sensitive nor specific for allergic
    rhinitis and should not be used exclusively for
    establishing the diagnosis.

34
Procedures
  • Rhinoscopy
  • Nasal provocation (allergen challenge) testing

35
Rhinoscopy
  •          While not routinely indicated, upper
    airway endoscopy (rhinolaryngoscopy) can be
    performed if a complication or comorbid condition
    may be present. It can be helpful for evaluating
    structural abnormalities (eg, polyps, adenoid
    hypertrophy, septal deviation, masses, foreign
    bodies) and chronic sinusitis (by visualizing the
    areas of sinus drainage).

36
Nasal provocation (allergen challenge) testing
  • This procedure is essentially a research tool
    and is rarely indicated in the routine evaluation
    of allergic rhinitis. The possible allergen is
    inhaled or otherwise inoculated into the nose.
    The patient can then be monitored for development
    of symptoms or production of secretions, or
    objective measurements of nasal congestion can be
    taken. Some consider this test the criterion
    standard test for the diagnosis of allergic
    rhinitis. However, it is not a practical test to
    perform routinely, and only an appropriately
    trained specialist should perform this test.

37
  • The management of allergic rhinitis consists of 3
    major categories of treatment,
  • environmental control measures and allergen
    avoidance,
  • pharmacological management,
  • immunotherapy

38
Environmental control measures and allergen
avoidance
  •          These involve both the avoidance of
    known allergens (substances to which the patient
    has IgE-mediated hypersensitivity) and avoidance
    of nonspecific, or irritant, triggers. Consider
    environmental control measures, when practical,
    in all cases of allergic rhinitis. However,
    global environmental control without
    identification of specific triggers is
    inappropriate.

39
Pollens and outdoor molds
  •          Because of their widespread presence in
    the outdoor air, pollens can be difficult to
    avoid. Reduction of outdoor exposure during the
    season in which a particular type of pollen is
    present can be somewhat helpful. In general, tree
    pollens are present in the spring, grass pollens
    from the late spring through summer, and weed
    pollens from late summer through fall, but
    exceptions to these seasonal patterns exist.
  •          Pollen counts tend to be higher on dry,
    sunny, windy days. Outdoor exposure can be
    limited during this time, but this may not be
    reliable because pollen counts can also be
    influenced by a number of other factors. Keeping
    the windows and doors of the house and car closed
    as much as possible during the pollen season
    (with air conditioning, if necessary, on
    recirculating mode) can be helpful. Taking a
    shower after outdoor exposure can be helpful by
    removing pollen that is stuck to the hair and
    skin.
  •          Despite all of these measures, patients
    who are allergic to pollens usually continue to
    be symptomatic during the pollen season and
    usually require some other form of management. As
    with pollens, avoidance of outdoor/seasonal molds
    may be difficult.

40
Indoor allergens
  • Depending on the allergen, environmental control
    measures for indoor allergens can be quite
    helpful. For dust mites, covering the mattress
    and pillows with impermeable covers helps reduce
    exposure. Bed linens should be washed every 2
    weeks in hot (at least 130F) water to kill any
    mites present. Thorough and efficient vacuum
    cleaning of carpets and rugs can help, but,
    ultimately, carpeting should be removed. The
    carpet can be treated with one of a number of
    chemical agents that kill the mites or denature
    the protein, but the efficacy of these agents
    does not appear to be dramatic. Dust mites thrive
    when indoor humidity is above 50, so
    dehumidification, air conditioning, or both is
    helpful.
  • Indoor environmental control measures for mold
    allergy focus on reduction of excessive humidity
    and removal of standing water. The environmental
    control measures for dust mites can also help
    reduce mold spores.
  • For animal allergy, complete avoidance is the
    best option. For patients who cannot, or who do
    not want to, completely avoid an animal or pet,
    confinement of the animal to a noncarpeted room
    and keeping it entirely out of the bedroom can be
    of some benefit. Cat allergen levels in the home
    can be reduced with high-efficiency particulate
    air (HEPA) filters and by bathing the cat every
    week (although this may be impractical).
    Cockroach extermination may be helpful for cases
    of cockroach sensitivity.

41
  • o        Occupational allergens As with indoor
    allergens, avoidance is the best measure. When
    this is not possible, a mask or respirator might
    be needed.
  • o        Nonspecific triggers Exposure to smoke,
    strong perfumes and scents, fumes, rapid changes
    in temperature, and outdoor pollution can be
    nonspecific triggers in patients with allergic
    rhinitis. Consider avoidance of these situations
    or triggers if they seem to aggravate symptoms.

42
Immunotherapy (desensitization)
  • A considerable body of clinical research has
    established the effectiveness of high-dose
    allergy shots in reducing symptoms and medication
    requirements. Success rates have been
    demonstrated to be as high as 80-90 for certain
    allergens. It is a long-term process noticeable
    improvement is often not observed for 6-12
    months, and, if helpful, therapy should be
    continued for 3-5 years. Immunotherapy is not
    without risk because severe systemic allergic
    reactions can sometimes occur. For these reasons,
    carefully consider the risks and benefits of
    immunotherapy in each patient and weigh the risks
    and benefits of immunotherapy against the risks
    and benefits of the other management options.

43
Immunotherapy
  • o        Indications Immunotherapy 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.
  • o        Administration Administer immunotherapy
    with allergens to which the patient is known to
    be sensitive and that are present in the
    patient's environment (and cannot be easily
    avoided). The value of immunotherapy for pollens,
    dust mites, and cats is well established. The
    value of immunotherapy for dogs and mold is less
    well established.
  • o        Contraindication A number of potential
    contraindications to immunotherapy exist and need
    to be considered. Immunotherapy should only be
    performed by individuals who have been
    appropriately trained, who institute appropriate
    precautions, and who are equipped for potential
    adverse events.

44
Surgical Care
  • Surgical care is not indicated for allergic
    rhinitis but may be indicated for comorbid or
    complicating conditions, such as chronic
    sinusitis, severe septal deviation (causing
    severe obstruction), nasal polyps, or other
    anatomical abnormalities. The value of
    turbinectomy is not established.

45
Second-generation antihistamines
  • Often referred to as the nonsedating
    antihistamines. They compete with histamine for
    histamine receptor type 1 (H1) receptor sites in
    the blood vessels, GI tract, and respiratory
    tract, which in turn inhibits physiologic effects
    that histamine normally induces at the H1
    receptor sites. Some do not appear to produce
    clinically significant sedation at usual doses,
    while others have a low rate of sedation. Other
    adverse effects (eg, anticholinergic symptoms)
    are generally not observed.
  • cetirizine, desloratadine, fexofenadine, and
    loratadine

46
Leukotriene receptor antagonists
  • Alternative to oral antihistamine to treat
    allergic rhinitis. One of the leukotriene
    receptor antagonists, montelukast (Singulair),
    has been approved in the United States for
    treatment of seasonal allergic rhinitis. When
    used as single agent, produces modest improvement
    in allergic rhinitis symptoms.

47
First-generation antihistamines
  • The older, first-generation H1 antagonists (eg,
    diphenhydramine, hydroxyzine) are effective in
    reducing most symptoms of allergic rhinitis, but
    they produce a number of adverse effects (eg,
    drowsiness, anticholinergic effects). They can be
    used prn, but adverse effects may limit their
    usefulness when taken on a daily basis. Some
    patients tolerate the adverse effects with
    prolonged use, but they may experience cognitive
    impairment, and driving skills may be affected.
    Administration at bedtime may help with
    drowsiness, but sedation and impairment of
    cognition may continue until the next day.

48
Decongestants
  • Stimulate vasoconstriction by directly
    activating alpha-adrenergic receptors of the
    respiratory mucosa. Pseudoephedrine produces weak
    bronchial relaxation (unlike epinephrine or
    ephedrine) and is not effective for treating
    asthma. Increases heart rate and contractility by
    stimulating beta-adrenergic receptors. Used alone
    or in combination with antihistamines to treat
    nasal congestion. Anxiety and insomnia may occur.
    Expectorants may thin and loosen secretions,
    although experimental evidence for their efficacy
    is limited. Numerous preparations are available
    containing combinations of various decongestants,
    expectorants, or antihistamines. Alternatively, a
    separate decongestant and antihistamine can be
    administered to allow for individual dose
    titration of each drug.

49
Nasal corticosteroids
  • Nasal steroid sprays are highly efficacious in
    treating allergic rhinitis. They control the 4
    major symptoms of rhinitis (ie, sneezing,
    itching, rhinorrhea, congestion). They are
    effective as monotherapy, although they do not
    significantly affect ocular symptoms. Studies
    have shown nasal steroids to be more effective
    than monotherapy with nasal cromolyn or
    antihistamines. Greater benefit may occur when
    nasal steroids are used with other classes of
    medication. They are safe to use and not
    associated with significant systemic adverse
    effects in adults (this may also be true for
    children, but the data are less clear).

50
Nasal corticosteroids
  • Local adverse effects are limited to minor
    irritation or nasal bleeding, which resolve with
    temporary discontinuation of the medication.
    Nasal septal perforations are rarely reported and
    are less common with the newer corticosteroids
    and delivery systems. Safety during pregnancy has
    not been established however, clinical
    experience suggests nasal corticosteroids
    (particularly beclomethasone, which has most
    experience in use) are not associated with
    adverse fetal effects.
  • The nasal steroids can be used prn, but seem to
    be maximally effective when used on a daily basis
    as maintenance therapy. They may also be helpful
    for vasomotor rhinitis or mixed rhinitis (a
    combination of vasomotor and allergic rhinitis)
    and can help to control nasal polyps.

51
Intranasal cromolyns
  • Produce mast cell stabilization and antiallergic
    effects that inhibit degranulation of mast cells.
    Have no direct anti-inflammatory or
    antihistaminic effects. Effective for
    prophylaxis. May be used just before exposure to
    a known allergen (eg, animal, occupational).
    Begin treatment 1-2 wk before pollen season and
    continue daily to prevent seasonal allergic
    rhinitis. Effect is modest compared with that of
    intranasal corticosteroids. Excellent safety
    profile and are thought to be safe for use in
    children and pregnancy.

52
Intranasal anticholinergic agents
  • Used for reducing rhinorrhea in patients with
    allergic or vasomotor rhinitis. No significant
    effect on other symptoms. Can be used alone or in
    conjunction with other medications. In the United
    States, ipratropium bromide (Atrovent Nasal
    Spray) is available in a concentration of 0.03
    (officially indicated for treatment of allergic
    and nonallergic rhinitis) and 0.06 (officially
    indicated for the treatment of rhinorrhea
    associated with common cold). The 0.03 strength
    is discussed.

53
Medical/Legal Pitfalls
  • o        While patients with allergic rhinitis
    may experience sedation and fatigue secondary to
    the disease process itself, sedation may occur
    due to medications. Most commonly, sedation is
    related to antihistamines, particularly the
    first-generation agents. In many states, driving
    while taking a first-generation, or sedating,
    antihistamine is illegal. Caution any patient who
    is taking a medication that has potential
    sedative effects about driving and operating
    heavy machinery.
  • o        A potential area of medicolegal concern
    is the failure to diagnose a comorbid condition
    or complication. Allergic rhinitis can occur in
    conjunction with other atopic diseases, such as
    asthma. Because asthma can be severe and even
    fatal, failure to diagnose concomitant asthma can
    lead to serious adverse events. Failure to
    diagnose potentially serious medical conditions
    that should be considered in the differential
    diagnosis of allergic rhinitis (eg, intranasal
    malignancy) might lead to serious consequences.
    Also, complications of allergic rhinitis (eg,
    sinusitis) can be serious and must be recognized
    when present.
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