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Allergic Conjunctivitis

General Information


  • allergic reaction in ocular and periocular tissues manifesting as eye redness (usually mild-to-moderate) with itching and swelling upon exposure to allergens1,2,3

Also Called

  • seasonal allergic conjunctivitis
  • perennial allergic conjunctivitis
  • atopic conjunctivitis


  • allergic conjunctivitis without corneal involvement1,2,3
    • traditionally classified as seasonal or perennial allergic conjunctivitis according to time period of allergen exposure
    • classification criteria proposed by the Spanish Society of Allergology and Spanish Society of Ophthalmology Consensus Document on Allergic Conjunctivitis (DECA Grade D)
      • intermittent vs. persistent
        • intermittent defined as ≤ 4 days/week or ≤ 4 consecutive weeks
        • persistent defined as > 4 days/week and > 4 consecutive weeks
      • severity
        • conditions
          • signs and symptoms bothersome
          • effect on vision
          • interference in school or work tasks
          • interference in activities of daily living
        • classification
          • mild disease if 0 conditions met
          • moderate disease in 1-3 conditions met
          • severe disease if 4 conditions met
      • PubMed25997302Journal of investigational allergology & clinical immunologyJ Investig Allergol Clin Immunol2015010125294-10694Reference - J Investig Allergol Clin Immunol 2015;25(2):94PDF
  • other types of allergic conjunctivitis (not addressed in this topic summary)1,2,3
    • contact dermatitis (type IV delayed hypersensitivity response) involving ocular surface, eyelids, and periocular skin
    • advanced/chronic allergic conjunctivitis
      • vernal keratoconjunctivitis
        • chronic allergic inflammation of ocular surface (cornea) mediated mainly by Th2-lymphocytes
        • symptoms include ocular itching (may be intense), redness, swelling, discharge, and photophobia
        • seasonally recurrent disease
        • most common in pediatric patients and in hot, dry environments such as the Mediterranean
      • atopic keratoconjunctivitis
        • bilateral chronic inflammatory disease of ocular surface (cornea) and eyelid
        • caused by chronic degranulation of mast cell mediated by IgE, and immune mechanisms mediated by Th1- and Th2-lymphocyte-derived cytokines
        • often accompanied by atopic dermatitis
        • can persist through all ages


General References Used

  1. La Rosa M, Lionetti E, Reibaldi M, et al. Allergic conjunctivitis: a comprehensive review of the literature. Ital J Pediatr. 2013 Mar 14;39:18full-text
  2. Friedlaender MH. Ocular allergy. Curr Opin Allergy Clin Immunol. 2011 Oct;11(5):477-82
  3. Bielory L, Meltzer EO, Nichols KK, Melton R, Thomas RK, Bartlett JD. An algorithm for the management of allergic conjunctivitis. Allergy Asthma Proc. 2013 Sep-Oct;34(5):408-20, commentary can be found in Allergy Asthma Proc 2015 Jul-Aug;36(4):79

Recommendation Grading Systems Used

  • Spanish Society of Allergology/Spanish Society of Ophthalmology consensus document on allergic conjunctivitis (DECA) uses Scottish Intercollegiate Guidelines Network (SIGN) grades of recommendation
    • levels of evidence
      • Level 1++ - high-quality meta-analyses, systematic reviews of randomized controlled trials (RCTs), or RCTs with very low risk of bias
      • Level 1+ - well-conducted meta-analyses, systematic reviews, or RCTs with low risk of bias
      • Level 1- - meta-analyses, systematic reviews, or RCTs with high risk of bias
      • Level 2++
        • high-quality systematic reviews of case-control or cohort studies
        • high-quality case-control or cohort studies with very low risk of confounding or bias and high probability that relationship is causal
      • Level 2+ - well-conducted case-control or cohort studies with low risk of confounding or bias and moderate probability that relationship is causal
      • Level 2- - case-control or cohort studies with high risk of confounding or bias and significant risk that relationship is not causal
      • Level 3 - non-analytic studies, such as case reports or case series
      • Level 4 - expert opinion
    • grades of recommendation
      • Grade A - ≥ meta-analysis, systematic review, or randomized controlled trial (RCT) rated as 1++, and directly applicable to the target population; or body of evidence consisting principally of 1++ studies, directly applicable to the target population, and demonstrating overall consistency of results
      • Grade B - evidence including 2++ studies, directly applicable to target population, and demonstrating overall consistency of results; or extrapolated evidence from 1++ or 1+ studies
      • Grade C - evidence including 2+ studies directly applicable to target population and demonstrating overall consistency of results; or extrapolated evidence from 2++studies
      • Grade D - evidence level 3 or 4, or extrapolated evidence from 2+studies
    • PubMed25997302Journal of investigational allergology & clinical immunologyJ Investig Allergol Clin Immunol2015010125294-10694Reference - consensus document on allergic conjunctivitis (DECA) (J Investig Allergol Clin Immunol 2015;25(2):94)

Synthesized Recommendation Grading System for DynaMed Content

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    • Strong recommendations are used when, based on the available evidence, clinicians (without conflicts of interest) consistently have a high degree of confidence that the desirable consequences (health benefits, decreased costs and burdens) outweigh the undesirable consequences (harms, costs, burdens).
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How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T115480, Allergic Conjunctivitis; [updated 2018 Nov 30, cited place cited date here]. Available from Registration and login required.

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