Term
| What is allergic rhinitis? |
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Definition
| IgE replaces normal IgG, causing inflammation of the nasal mucosa in response to an allergen - congestion, rhinorrhea, sneezing, itching. Very common |
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Term
| What are risk factors for allergic rhinitis? |
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Definition
- Genetics
- Allergen exposure by region
- Serum igE > 100 before age 6
- high socioeconomic class due to hygiene
**Early exposure is a protective factor. |
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Term
| How is allergic rhinitis classified? |
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Definition
- Seasonal vs perennial
- Mild (does not interfere w/ sleep or work) or moderate/severe
- Intermittent (less than 4 days/week or less than 4 weeks) or Persistant (more than 4 days/week or more than 4 weeks) |
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Term
| What are the functions of the nasal mucosa? |
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Definition
- Heat the air
- Humidify the air
- Clean - by lymph tissue |
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Term
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Definition
| Protein components in airborne pollen, grain, weeds |
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Term
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Definition
An allergen produces an IgE antibody - infiltration by TH2 cells. A type 1 hypersensitivity reaction
**IgE is bound to mast cells and basophils |
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Term
| What is the role of mast cells? |
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Definition
| Antigen + IgE on mast cell surface --> degranulation and release of histamine (primary mediators), synthesis of secondary mediators |
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Term
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Definition
| Allergen + APC attract CD4+ helper T cell --> production of B cells, plasma cells, and eventually IgE antibodies. |
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Term
| What is the early phase reaction? |
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Definition
Allergen + IgE antibodies on mast cell --> degranulation and histamine. Action on: Blood vessels (congestion and edema), Mucous glands (Rhinorrhea), nerves (sneezing)
**Sneezing and rhinorrhea are most common symptoms. |
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Term
| What is the late phase reaction? |
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Definition
Allergen + IgE on mast cell --> infiltration with eosinophils, basophils, TH2, and monocytes.
Leads to congestion and hyperresponsiveness.
**Congestion predominates. |
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Term
| What are typical symptoms of allergic rhinitis? |
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Definition
- clear watery rhinorrhea - Tx w/ intranasal anticholinergic + intranasal steroid
- Sneezing
- Nasal congestion ~24 hrs post-exposure
- Itchy eyes, nose. Allergic conjuctivitis.
**In children: allergic shiners, allergic salute |
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Term
| What could allergic rhinitis be confused with? |
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Definition
- Infectious rhinitis - viral infection
- NARES - negative skin test, no IgE
- Drug-induced rhinitis |
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Term
| What are avoidance strategies for allergic rhinitis? |
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Definition
- Home humidity < 50%
- Remove pets
- Dust mite elimination
- Avoid outdoors when pollen count is high. |
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Term
| What is 1st line Tx for mild, intermittent allergic rhinitis? |
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Definition
2nd generation antihistamines - make receptor less available. Less anticholinergic effects
- Cetirizine/Zyrtec - OTC. some sedation
- Levocetirizine/Xyzal - Rx
- Loratadine/Claritin - OTC
- Desloratidine/Clarinex - Rx
- Fexofenadine/Allegra - OTC
**Take 1-2 hours before allergen exposure, with water |
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Term
| What are intranasal options for allergic rhinitis? |
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Definition
- Intranasal antihistamines - less effective than steroids. Azelastine/Astelin or Astepro, Olopatadine/Patanase. Do not help w/ congestion.
- Intranasal corticosteroids - 1st LINE RX: Beclomethasone/Beconase, Budesonide/Rhinocort, Ciclesonide/Omnaris, Fluticasone/Flonase, Mometasone/Nasonex, Triamcinolone/Nasacort |
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Term
| What steroid should not be use in children with allergic rhinitis? |
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Definition
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Term
| When is montelukast/Singulair used? |
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Definition
As a last line agent - inhibits the leukotriene receptor
Antihistamine + Singulair is LESS effective than a nasal steroid |
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Term
| How does Cromolyn/Nasalcrom work? |
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Definition
| Inhibits mast cell degranulation - for prevention and tx of allergic rhinitis |
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