1. Allergic Rhinitis

2. References
Allergic rhinitis management pocket reference Allergy 2008: 63: 990–996.
Pharmacotherapy: A pathophysiologic Approach. 7th Edition 2008.
Safety of Antihistamines in Children. Drug Safety 2001; 24 (2):
Second-Generation Antihistamines Actions and Efficacy in the Management of Allergic Disorders. Drugs 2005; 65 (3):

3. allergic rhinitis
<immunology> An inflammatory response in the nasal passages to an allergic stimulus. Often includes: nasal congestion, sneezing, runny or itchy nose

4. Allergic Rhinitis The most common atopic disease
The hallmark of ~: a temporal relationship between the exposure to allergens & the development of nasal symptoms
It takes at least 2 years of exposure to aeroallergens (airborne environmental allergens) to develop AR (thus, very rare in children <1 year)
The prevalence of AR: lowest in children < 5 yrs
highest 2nd---- 4th decades
Genetic predisposition (60%)

5. In a sensitized individual, allergic rhinitis occurs when mucous membranes are exposed to inhaled allergenic materials that elicit a specific response mediated by immunoglobulin E (IgE).

6. Allergen sensitization and the allergic response. A. Exposure to
antigen stimulates IgE production and sensitization of mast cells with antigen specific
IgE antibodies. B. Subsequent exposure to the same antigen produces an
allergic reaction when mast cell mediators are released.

7. Mast cells degranulating and releasing vasoactive amines.
Mast cells release a variety of preformed (histamine, heparin, tryptase, chymotryptase and carboxypeptidase) and newly synthesized lipid (LTB4, LTC4, PGD2 and platelet activating factor) and cytokines.
Mast cells degranulating and releasing vasoactive amines.

8. Classification AR is classified as seasonal or perennial
Seasonal: repetitive and predictable symptoms (severe)
Perennial: symptoms persist throughout the year without any obvious seasonal pattern
WHO: replace terms with intermittent or persistent

10. Allergic Rhinitis Most patients develop symptoms before age 30
Asthma develops in about 19% of children with rhinitis (more likely with perrenial allergic rhinitis)
The term “rhinitis” refers to the inflammation of the nasal mucous membranes. Whenever a a causative allergen can be identified allergic rhinitis
It is difficult sometimes to distinguish between different types of rhinitis
Comparison between different types of rhinitis

11. Features of Common Rhinitis Symptoms
Allergic rhinitis
Infectious rhinitis
Vasomotor rhinitis
Rhinitis Medicamentosa
Etiology
Allergen
Viral or bacterial
Unknown
Tachyphylaxis to topical decongestants
Symptoms
Rhinorrhea, congestion, sneezing, pruritis, cough with postnasal drip ocular itching etc
Fever (more common in children), mucupurulent rhinorrhea, scratchy throat, congestion, cough
Rhinorrhea, congestion
Congestion
Pattern
Perennial or seasonal
Any time
Temporal relationship with use of topical decongestant
Associated Factors
Concurrent atopic disease, family history
None
Affects women primarily, strong odours, alcohol, stress, change in humidity and temperature
Overuse of topical decongestants, concurrent use of antihypertensive therapy

12. Perennial Allergic Rhinitis 1
Caused by continuous exposure to many different types of allergens
Dust Mite the most common cause of perennial allergic rhinitis
Commonly: household dust mites, molds, cockroaches, house pets
Less commonly: cottonseed & flaxseed (found in fertilizers, hair setting preparations and foods); some vegetable gums (found in hair setting prep & foods)

13. Caused by:
Dust mites

14. Perennial Allergic Rhinitis 2
Dust mite: thrive in carpets, beddings & reproduce best in warm (18-21ºC) humid (>50%) environment found in most homes
Mites feed on human skin scales and their own faeces.
Mite itself is not allergen, the main allergen is the glycoprotein that coats their faeces.
Dust mite remain airborne for about 30 minutes after being disturbed
Molds: grow best in warm, moist environment
Cat-derived allergens: light small proteins secreted through the sebaceous glands in the skin. May remain airborne for up to 6 hrs. Can be detected at home even 6 months after removal of the cat.
mites
Any arthropod of the order acarina except the ticks. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on man and domestic animals, producing various irritations of the skin (acariasis or mite infestations). Many mite species are important to human and veterinary medicine as both parasite and vector.

15. Seasonal Allergic Rhinitis
Caused by wind-borne plant pollens (e.g. tree, grass. etc)
“hay fever”, and “rose fever” are terms related to seasons associated grass pollinosis and NOT associated with FEVER!
Symptoms of perennial allergic rhinitis are similar but less severe than those associated with seasonal AR
Symptoms maybe associated with: (1) specific activities (e.g. vaccuming the carpet) (2) certain environments (e.g. cigarette smoke)

17. Complications Sinusitis Recurrent otitis media & hearing loss
Patients who develop:
fever,
purulent nasal discharge,
frequent HA,
earache
refer to Dr. for evaluation and treatment
Chronic obstruction around the sinus ostia and eustachian tube increases the risk of sinusitis, recurrent otitis media and eustachian tube dysfunction

18. Symptoms of Allergic Rhinitis
Ocular: itching, lacrimation, mild soreness, puffiness & conjuctival erythema
Nasal: congestion, watery rhinorrhea, itching, sneezing, postnasal drip and nasal pruritus
Head & Neck: loss of taste and smell, mild sore throat due to postnasal drip, earache, sinus HA, itching of the palate and throat
Systemic: malaise & fatigue:
malaise
A vague feeling of bodily discomfort.

20. Physical Assessment “allergic shiners”  venous/lymphatic congestion
Chronic mouth breathing highly arched palate
A horizontal crease across the lower third of the nose (in patients repeatedly rub their noses upward) called “nasal salute”
Nasal mucosa: pale & swollen
Nasal secretions: clear & watery
Eyes: watery with scleral & conjuctival erythema and periorbital edema

21. Arched palate because of mouth breathing
Allergic shiners
Arched palate because of mouth breathing
Periorbital edema

23. Uncomplicated allergic rhinitis does not cause fever, significant sore throat, vomiting or diarrhoea
 these symptoms suggest viral or bacterial infection refer to doctor