Excerpt from Keratoconjunctivitis, Atopic
Synonyms, Key Words, and Related Terms: atopic keratoconjunctivitis, AKC, bilateral conjunctivitis, atopic dermatitis, allergic conjunctivitis, giant papillary conjunctivitis, vernal keratoconjunctivitis, systemic allergy
Background: Atopic keratoconjunctivitis (AKC) is a relatively uncommon but potentially blinding ocular condition. In 1952, Hogan described AKC as a bilateral conjunctivitis occurring in 5 male patients with atopic dermatitis. Originally described to flare with worsening dermatitis, Foster et al noted that some patients’ ocular involvement evolves independent of dermatitis.
AKC is associated with a 95% prevalence of concomitant eczema and an 87% prevalence of asthma. Other than AKC, common ocular atopic phenomena include allergic conjunctivitis, giant papillary conjunctivitis, and vernal keratoconjunctivitis. Pathophysiology:
Atopy refers to hypersensitivity in patients with familial histories of allergic disease. Individuals with atopy often have environmental allergies, allergic asthma, rhinitis, and atopic dermatitis or eczema. Less commonly, they exhibit food allergies, urticaria, and nonhereditary angioedema. Immunoglobulin E (IgE) is the serum mediator of the exuberant responses. Hypersensitivity reactions associated with types I and IV contribute to the inflammatory changes of the conjunctiva and the cornea that are found in AKC. During exacerbations, patients have increased tear and serum IgE levels and increased numbers of circulating B cells; T-cell levels are depressed.Frequency:
- Internationally: Atopy affects 5-20% of the general population. AKC occurs in 20-40% of individuals with atopic dermatitis.
Mortality/Morbidity: Decreased vision and blindness result from chronic superficial punctate keratitis, persistent epithelial defects, corneal scarring or thinning, keratoconus, cataracts, and symblepharon formation. The use of corticosteroids to medically treat AKC can further promote the development of cataracts, glaucoma, and secondary corneal infections.
Sex: This condition is more prevalent in men than in women.
Age: Peak age of incidence is in persons aged 30-50 years. The age range is from the late teenaged years to 50 years.
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