Nasal allergy

Antihistamines are drags used to counteract the effects of histamine on body organs and structures. Examples of antihistamines include diphenhydramine (Benadryl), loratadine (Claritin), fexofenadine (Allegra), and cetirizine (Zyrtec). A new antihistamine, deslorata-dine (Clarinex), is die active metabolite of loratadine and is intended to eventually replace loratadine (Claritin). Topical corticosteroid nasal sprays such as fluticasone propionate (Flonase) or triamcinolone ace-tonide (Nasacort AQ) are also used for nasal allergy symptoms. See Chapter 56 for more information on die topical corticosteroids. 

Jahnsen FL, Lund-Johansen F, Dunne JF, parkas L, Haye R, Brandtzaeg P Experimentally induced recruitment of plasmacytoid (CD123 ) dendritic cells in human nasal allergy. J Immunol 2000 165 4062-4068. 

Sofradex contains dexamethasone, framycetin and gramicidin and is indicated in otitis externa. Canesten contains clotrimazole and is indicated for fungal infections and may be used in otitis externa where a fungal infection is suspected. Nasonex contains mometasone, a corticosteroid, and is used in nasal allergy. 

An important example of PLP-dependent amino acid decarboxylation is the conversion of histidine into histamine. Histamine is often involved in human allergic responses, e.g. to insect bites or pollens. Stress stimulates the action of the enzyme histidine decarboxylase and histamine is released from mast cells. Topical antihistamine creams are valuable for pain relief, and oral antihistamines are widely prescribed for nasal allergies such as hay fever. Major effects of histamine include dilation of blood vessels, inflammation and swelling of tissues, and narrowing of airways. In serious cases, life-threatening anaphylactic shock may occur, caused by a dramatic fall in blood pressure. 

Figure 9.2 Diagram of the four cell types in the nasal respiratory epithelium. A ciliated columnar cell covered by cilia and microvilli of uniform length B basal cell C goblet cell packed with mucus granules D nonciliated columnar cell, covered by microvilli of uniform length. (Redrawn from Mygind, N., 1979 Nasal Allergy, 2nd edition. Blackwell Scientific Publications Oxford).

Intranasal administration may be used for local or systemic effects. Local effects include treatment of nasal allergies, rhinitis, and nasal congestion. Nasal delivery for systemic effects is established for a small number of drugs and is being examined for many others. 

Mygind, N. Nasal Allergy Blackwell Scientific Publications London, 1979 260. 

Maguchi S, Fukuda S. Taxus cuspidata (Japanese yew) pollen nasal allergy. Auris Nasus Larynx 2001 28 (Suppl) S43-7. 

If a major salivary gland is lost from trauma or disease, or if nasal allergies or sinus infections cause persistent mouth-breathing, or if tobacco smoking persists, the oral cavity becomes dry (xerostomia). The oral mucosa and teeth become covered with bacteria and dental caries and periodontal disease become difficult to control. The functions of whole... 

Tsunoda K, Ohta Y, Shinogami M, Soda Y Does passive smoking affect the incidence of nasal allergies Am J Public Health 1995 85 1019-1020. 

Mygind, N. 1979. Nasal allergy. Oxford Blackwell Scientific. 

Based on its mechanism of action, omalizumab has been used in the treatment of other allergic disorders, such as nasal allergy and food allergy, but large-scale clinical trials are limited to asthma. 

Ito H, Nishimura J, Suzuki M, Mamiya S, Sato K, Takagi I, Baba S. Specific IgE to Japanese cypress (Chamaecyparis obtusa) in patients with nasal allergy. Ann Allergy Asthma Immunol 1995 74(4) 299-303. 

Durahm SR, Gould HJ, Hamid QA. Local IgE production in nasal allergy. Inti Arch Allergy Immunol 1997 113 128-130... 

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