2020–2021 BCSC Basic and Clinical Science Course™
8 External Disease and Cornea
Chapter 11: Diagnosis and Management of Immune-Related Disorders of the External Eye
Immune-Mediated Diseases of the Eyelid
Atopic Dermatitis
PATHOGENESIS
Atopic dermatitis is a chronic condition in genetically susceptible individuals that usually begins in infancy or childhood and may or may not involve the external eye. The pathogenesis of atopic dermatitis involves a type IV hypersensitivity reaction, increased IgE hypersensitivity, an increase in histamine released from mast cells and basophils, and impaired cell-mediated immunity.
CLINICAL PRESENTATION
Diagnostic criteria for atopic dermatitis include pruritus, lesions on the eyelid and other sites (eg, joint flexures in adolescents and adults, face and extensor surfaces in infants and young children), and a personal or family history of other atopic disorders, such as asthma, allergic rhinitis, nasal polyps, and aspirin hypersensitivity. Other ocular findings include periorbital darkening, exaggerated eyelid folds, meibomianitis, ectropion, and chronic papillary conjunctivitis. The appearance of the skin lesions varies depending on the age of the patient. Infants typically have an erythematous rash, children tend to have eczematous dermatitis with secondary lichenification from scratching, and adults have scaly patches with thickened and wrinkled dry skin.
MANAGEMENT
Allergens in the environment and in foods should be identified and minimized whenever possible. In general, the services of an allergist should be sought. Moisturizing lotions and petrolatum gels can be useful for skin hydration. Acute lesions can be controlled with a topical corticosteroid cream or ointment (clobetasone butyrate 0.05%), but long-term use of such medications is strongly discouraged to avoid skin thinning and ocular complications of corticosteroids (eg, cataract, glaucoma). Topical tacrolimus ointment 0.03% or 0.1% is also effective and has fewer adverse effects. Oral antipruritic agents such as antihistamines and mast-cell stabilizers can alleviate itching but may exacerbate dry eye with their anticholinergic activity.
Guglielmetti S, Dart JK, Calder V. Atopic keratoconjunctivitis and atopic dermatitis. Curr Opin Allergy Clin Immunol. 2010;10(5):478–485.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.