Allergies

Question 1

What is released by mast cells upon contact with allergens?

Answer 1

Histamines, Cytokines, prostaglandines and more

Question 2

The sequence of allergens and allergic reaction:

Answer 2

Allergen enters mucous membrane (nose) -> taken up by APC to T-cells -> T cells stimulate B-cells to produce IgE antibodies -> IgE antibodies sit on the surface of mast cells -> mast cells have granules containing mediators like histamine and prostaglandins

-> allergens bind to the IgE antibodies on the mast cells causing the release of the mediators -> the mediators like histamine cause vasodilation and increased permeability of the blood vessels -> nasal stuffiness, sneezing, and mucus discharge

Question 3

How do Anit-Histamines work?

Answer 3

Blocking of receptors of histamines receptors on blood vessels -> preventing vasodilation and material from moving into the tissue

Question 4

What type of therapies against allergies?

Answer 4

-Antihistamines, Mast stabilizers, Vasoconstrictor

Question 5

Which three allergic diseases have a genetic component involved?

Answer 5

Allergic Rhinitis, Allergic dermatitis, Asthma

-If patients have one there is a possibility that they have more or all three

Question 6

Which three allergic diseases have a genetic component involved?

Answer 6

Allergic Rhinitis, Allergic dermatitis, Asthma

-If patients have one there is a possibility that they have more or all three
-Treating allergic rhinitis might help patients with their asthma

Question 7

What are the risk factors for allergic Rhinitis?

Answer 7

-Family history
-elevated Ige
-Smoking
-exposure to allergens:
seasonal -> pollen
perennial -> dust mites, pet hair

Question 8

Which drugs induce Rhinitis?

Answer 8

-ACE-inhibitor
-Phosphodiesterase-5 selective inhibitors
-Phentolamine
-Alpha-receptor antagonists used for blood pressure, prostate, cause vasodilation
-NSAIDs including aspirin
-Oral contraceptives

15-20% of patients treated will be associated with Rhinitis caused by these drugs

Question 9

When is Rhinits considered nonallergic?

Answer 9

When IgE is not the causing factor
-Hormonal, structural (deviated nose-septum), drug-induced, trauma

Question 10

What are some complications:

Answer 10

Polyps, sleep apnea, decreased sense of smell

Question 11

What are the treatment options?

Answer 11

Nondrug (avoid allergens, nasal wetting agents)
-Intranasal corticosteoroids
-Antihistamines: 1st and 2nd than intranasal
-Mast cell stabilizer
-Dietary supplements

Question 12

Nasal wetting agents:

Answer 12

-removes nasal dryness and crusting
-well tolerated, may cause stinging and burning bc of the formulation (not isotonic)

-the device has to be cleaned and the wash mixture discarded after nasal rinsing -> may cause infections

-use boiled or distilled water

Question 13

How do Corticosteroids work?

Answer 13

They limit T-cell and B-cell operation

Question 14

Intranasal Corticosteorids: Flonase

Answer 14

-API: Fluticasone propionate
-for runny nose, sneezing,
-side effects: Epistaxis (nose bleeding) caused by the administration and thinning of mucus layer due to steoroids

Question 15

Intranasal Corticosteorids: Flonase
Alternatives: Nasacort (API: Triamcinolone acetonide),
Rhinocort (API: Budesonide)

Answer 15

-API: Fluticasone propionate
-for runny nose, sneezing,
-side effects: Epistaxis (nose bleeding) caused by the administration and thinning of mucus layer due to steroids

Question 16

Do INCS decrease terminal growth due to steroids?

Answer 16

-There is no evidence that nasal sprays (asthma meds) decrease terminal growth but they may decrease growth velocity in high concentration

Question 17

First Gen Sedating Antihistamines: Benadryl + Chlor-Trimeton

Answer 17

API: Diphenhydramine hydrochloride
-Indication: Allergy symptoms and sleep aid
-Side effects: Drowsiness, dizziness
-Drug interaction: CNS depressants, Anticholinergics (blocks ACh, for parasympathetic)
-for 6-12y and adults NOT elderly

API: Chlorpheniramine maleate
-Indication, the side effect is the same
-for 6-12y and adults NOT elderly (listed in beers criteria)

Question 18

When should First Gen Sedation Antihistamine NOT be used?

Answer 18

-Patients with
-Breathing problems, problem urinating due to enlarged prostate, Glaucoma, Dementia -> often in older patients

Question 19

Second Gen Sedating Antihistamines: Claritin and Allegra
(Nonsedating bc they don’t cross the blood-brain barrier easily compared to the first generation)

Answer 19

Claritin (Alavert)
-API: Loratadine
-Indication: Allergy symptoms
-Side effects: Headache, Xerostomia (dry mouth)
-Drug interaction: Amiodarone (QT prolongation, irregular heart rhythm)
-Age: 8 and above, CAUTION with elder people

Allegra
-API: Fexofenadine hydrochloride
Drug interaction: problems with absorption when taken with magnesium antacids or fruit juice
-Age: 8 and above, CAUTION with elder people

Other examples:
Zyrtec / Xyzal -> API: Cetirizine HCl / levocetirizine dihydroCl

Question 20

Mast cell stabilizer: NasalCrom

Answer 20

-API: Cromolyn sodium
-are very effective, it is a preventive product
not for treatment
-have to be taken 2 weeks in advance, bs, when the histamines are released stabilizing the mast cells, won’t help anymore
-its efficacy and onset are lower than intranasal steroids

Question 21

Mast cell stabilizer profile

Answer 21

-For allergic symptoms
-Side effects: nasal irritation
-Age: 2y and older
-Plower absorption in pregnant women

Question 22

When are intranasal CS and when are Oral Antihistamines preferred?

Answer 22

In intermitted allergies: Oral AH 2G is the first line bc they work pretty quickly (60min), is reasonable and the patient doesn’t need it all the time
2. Intranasal AH (faster onset)
3. OAH 2G with vasoconstrictor
4. Intranasal Corticosteroid

For persistent allergies, Intranasal CS is the first line followed by Antihistamines

Question 23

How do Corticosteroids work?

Answer 23

They limit T-cell and B-cell operation