ALLERGIC CONJUNCTIVITIS - 10/09/11

Doi : 10.1016/S0889-8561(05)70288-5

Leonard Bielory, MD ^{^{*
From the Division of Ophthalmology, Scripps Clinic and Research Foundation, La Jolla, California (MHF); the Division of Rheumatology and Immunology, Harvard Medical School, Boston, Massachusetts (HF); and the Division of Allergy and Immunology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey (LB)}}, Mitchell H. Friedlaender, MD ^{^{*
From the Division of Ophthalmology, Scripps Clinic and Research Foundation, La Jolla, California (MHF); the Division of Rheumatology and Immunology, Harvard Medical School, Boston, Massachusetts (HF); and the Division of Allergy and Immunology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey (LB)}}, Hiroshi Fujishima, MD ^{^{*
From the Division of Ophthalmology, Scripps Clinic and Research Foundation, La Jolla, California (MHF); the Division of Rheumatology and Immunology, Harvard Medical School, Boston, Massachusetts (HF); and the Division of Allergy and Immunology, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey (LB)}}

Résumé

Allergic conjunctivitis affects approximately 25% of the general population, and is a common clinical problem for ophthalmic and allergic practices.^{17 Friedlaender M.H. Current concepts in ocular allergy Ann Allergy 1991 ; 67 : 5-13

Cliquez ici pour aller à la section Références} In one study of 5000 allergic children, 32% had ocular disease as the single manifestation of their allergies.^{33 Marrache F., Brunet D., Frandeboeuf J. , et al. The role of ocular manifestations in childhood allergy syndromes Rev Fr Allergol Immunol Clin 1978 ; 18 : 151-155 [cross-ref]

Cliquez ici pour aller à la section Références} Although many cases are seasonal, a large number of patients have year-round symptoms. Ocular allergies have been touted to compose 10% of ophthalmologic practice, 25% of allergy/clinical immunologic practice, and 5% of the general pediatric and internal medicine practice; however, the various definitions and treatment regimens make them difficult to diagnose and frustrating to treat.

The conjunctiva can be affected by allergies to airborne pollens, animal dander, and other environmental antigens. The conjunctiva, like the nasal mucosa, is an active immunologic tissue that undergoes lymphoid hyperplasia in response to a stimulant.^{26 Isaacson P., Wright D.H. Extranodal malignant lymphoma arising from mucosa-associated lymphoid tissue Cancer 1984 ; 53 : 2515-2524 [cross-ref]

Cliquez ici pour aller à la section Références} The conjunctiva represents a thin mucous membrane that extends from the limbus of the eye to the lid margin of the eyelid. The conjunctiva is divided into three portions: the bulbar conjunctiva, which covers the anterior portion of the sclera; the palpebral conjunctiva, which lines the inner surface of the eyelids; and the space bounded by the bulbar and palpebral conjunctiva, which is the fornix or the conjunctival sac. The conjunctiva is histologically divided into two layers: epithelial and substantia propria layers. The epithelial layer is composed of 2 to 5 cells of stratified columnar cells whereas the lamina propria is composed of loose connective tissue.

As in other forms of allergic inflammation, the mast cell plays a key role. Mast cells are widely distributed, especially in connective tissue and mucosal surfaces. In the eye they are classically found in the conjunctiva, choroid, ciliary body, iris, and optic nerve. Mast cells (6000/mm³) and other inflammatory cells are normally found in the substantia propria, just below the epithelial junction. Initial reports of conjunctival mast cell populations were based on the differential physiological response to compound 48/80 which causes connective tissue mast cells to degranulate, but not mucosal mast cells. In the rat animal model the response to a single application of 48/80 suggested that the conjunctival mast cells primarily belong to the connective tissue type of mast cells.^{5 Barney NP, Briggs RM, Bloch KJ, et al: Mast cell subpopulations in the conjunctiva. 66(14a)

Cliquez ici pour aller à la section Références} Mononuclear cell populations of the normal human conjunctiva are primarily located in the epithelium and include Langerhans' cells (CD1⁺; 85 ± 16 cells/mm²) and CD3⁺ lymphocytes (189 ± 27 cells/mm²) with a CD4⁺/CD8⁺ ratio of 0.75.^{40 Soukiasian S.H., Rice B., Foster C.S. , et al. The T cell receptor in normal and inflamed human conjunctiva Invest Ophthalmol Vis Sci 1992 ; 33 : 453-459

Cliquez ici pour aller à la section Références} The Langerhans' cells are known to facilitate immune reactions in the skin by functioning as an antigen-presenting cell, but their function in the cornea has yet to be clarified.^{22 Gillette T.E., Chandler J.W., Geiner J.V. Langerhans' cells of the ocular surface Ophthalmol 1982 ; 89 : 700-711

Cliquez ici pour aller à la section Références} Interestingly, the Langerhans' cells of the eye are recognized by the CD1⁺ marker, but not the CD6⁺ thymocyte marker, which is commonly found on Langerhans' cells of the skin or in histiocytes from patients with histiocytosis X.^{36 Seto S.K., Gillete T., Chandler J.W. HLA-DR+/T6⁻ Langerhans' cells of the human cornea Invest Ophthalmol Vis Sci 1987 ; 28 : 1719-1722

Cliquez ici pour aller à la section Références} Normal ocular epithelium does not contain any mast cells, eosinophils, or basophils, although in ocular inflammatory disorders, such as vernal and giant papillary conjunctivitis, such cells are seen, as evidenced by the conjunctival deposition of eosinophil major basic protein deposition^{43 Trocmé S.D., Kephart G.M., Allansmith M.R. , et al. Conjunctival deposition of eosinophil granule major basic protein in vernal conjunctivitis and contact lens-associated conjunctivitis Am J Ophthalmol 1989 ; 108 : 57-63

Cliquez ici pour aller à la section Références}; however, conjunctival epithelial cells may also play an active role in allergic inflammation as they have been shown to express RANTES in large amounts when stimulated with tumor necrosis factor-⍺ or interferon-γ in vitro.^{20 Fukagawa K., Saito H., Tachimoto H. , et al. RANTES production in cultured human conjunctival epithelial cell line J Allergy Clin Immunol 1996 ; 97 : 441

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Histamine concentration in tears can reach values greater than 100 ng/mL compared with normal values of 5 to 15 ng/mL.^{25 Histamine levels of tears during allergic conjunctivitis: Physiopathology and therapy with disodium chromoglycate Chibret Int J Ophthalmol 1985 ; 3 : 16

Cliquez ici pour aller à la section Références} Histamine can cause similar changes in the eye, as it does in other parts of the human body, which include capillary dilatation, increased vascular permeability, and smooth muscle contraction. Histamine concentration of 240 nmol/L (10 μL of a 50 ng/mL histamine phosphate concentration) can cause conjunctival redness and increased vascular permeability in 50% of the subjects studied. Tear histamine levels found in nonatopic controls are not different than allergic patients during their symptom-free periods.^{27 Kari O., Sari O.P., Halmepuro L. , et al. Tear histamine during allergic conjunctivitis challenge Graefes Arch Clin Exp Ophthalmol 1985 ; 223 : 60 [cross-ref]

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Plan

HISTORY

EXAMINATION

SEASONAL AND PERENNIAL ALLERGIC CONJUNCTIVITIS

Seasonal Allergic Conjunctivitis

Perennial Allergic Conjunctivitis

Address reprint requests to Mitchell H. Friedlaender, MD, Division of Ophthalmology, MS214, Scripps Clinic and Research Foundation, 10666 North Torrey Pines Road, La Jolla, CA 92037