Viral conjunctivitis followed by bacterial conjunctivitis are the most common causes of infectious conjunctivitis

Viral conjunctivitis followed by bacterial conjunctivitis are the most common causes of infectious conjunctivitis.[15,25,81] The majority of viral conjunctivitis cases are due to adenoviruses,[28] and the use of quick antigen test to diagnose adenoviral conjunctivitis may present an appropriate strategy to avoid overuse of antibiotics. and appropriate treatment. and levels of specific serum IgE may be used; however, the diagnosis of allergic conjunctivitis remains a clinical one. Viral conjunctivitis Viral conjunctivitis is the most common overall cause of infectious conjunctivitis, and it is usually secondary to inoculation of the ocular surface with the adenoviruses.[25,26] Less frequently, other viruses may be the underlying etiology in viral conjunctivitis; amongst them, herpes simplex virus (HSV), varicella zoster computer virus (VZV), and enterovirus have been the subject of investigation.[27] Adenoviral conjunctivitis As the leading cause of infectious conjunctivitis worldwide, up to 90% of viral conjunctivitis cases are caused by adenoviruses.[28] Recent advances in genome sequencing of human adenoviruses GB-88 (HAdV) have identified over 72 unique HAdV genotypes classified into seven different species (HAdV-A through HAdV-G), with HAdV-D species having the most members and the strongest association with viral conjunctivitis.[29,30] Perhaps the most common form of infection by the adenoviruses in children is pharyngoconjunctival fever (PCF) caused by HAdV types 3, 4, and 7.[31,32,33] This condition is usually characterized by the presence of fever, pharyngitis, periauricular lymphadenopathy, and acute follicular conjunctivitis. Additional ocular surface findings include edema, hyperemia, and petechial hemorrhages of the conjunctiva as a result of conversation between pro-inflammatory cytokines and conjunctival vasculature.[32] This condition is self-limited, often resolving spontaneously in twoCthree weeks without any treatment. The most severe ocular manifestation of adenoviral contamination is the epidemic keratoconjunctivitis (EKC); this condition affects both the conjunctiva and cornea, leaving behind long-lasting and permanent ocular surface changes and visual disturbances. Ocular manifestations of EKC include conjunctival discharge, follicular conjunctivitis, corneal subepithelial infiltrates (SEI), corneal scarring, development of conjunctival membranes and Mouse monoclonal to pan-Cytokeratin pseudomembranes, and symblepharon formation (Figures 1 and 2). Open in a separate window Physique 1 Adenoviral conjunctivitis presenting as bilateral watery eyes. Open in a separate window Physique 2 Pseudomembrane formation in a patient with adenoviral conjunctivitis. Open in a separate window Physique 3 Subepithelial infiltrations in a patient with adenoviral conjunctivitis. Classically, serotypes 8, 19, 37, and less frequently serotype 4 were believed to be associated with EKC, but more recently, HAdV-D53 and HAdV-D54 have been identified in several outbreaks and are thought to be responsible for GB-88 the majority of EKC cases.[30] Pseudomembranes, which are linens of fibrin-rich exudates without blood or lymphatic vessels, may be encountered in the tarsal conjunctiva of the EKC patients.[35] Depending on the intensity of inflammation, true conjunctival membranes may also form in EKC. True membranes, once form, can lead to the development of subepithelial fibrosis and symblepharon; additionally, they tend to bleed severely upon removal. [36] Cornea is usually another tissue that may become adversely affected in EKC. Replication of the computer virus in the corneal epithelium may cause superficial punctate keratopathy, followed by focal areas of epithelial opacities.[37] Focal SEI in the anterior stroma of the cornea appears approximately 7C10 days following the initial involvement of the eyes with EKC[38] (Determine 3). These opacities may persist for years, and they may be associated with visual disturbance, photophobia, and astigmatism. The incidence of SEI formation in EKC has been reported to vary from 49.1 to 80%.[39] An immunologic reaction to the replicating adenoviruses in anterior stromal keratocytes is hypothesized to be the underlying mechanism for the formation of SEIs. The observation that these opacities recur following discontinuation of steroids supports the hypothesis.[40] Adenovirus conjunctivitis is very contagious and it may be transmitted up to 50% of the time according to some reports.[41,42] The virus may spread through contaminated fingers, medical devices, contaminated water at the swimming pools, or by sharing of personal items; as many as 46% of individuals with viral conjunctivitis experienced positive viral culture grown from their hands according to one study.[43] The adenovirus is a very hardy organism, and it GB-88 is reported to be resistant to 70% isopropyl alcohol and 3% hydrogen peroxide.[44] The American Academy of Ophthalmology recommends using.