(Pharyngoconjunctival Fever & Epidemic Keratoconjunctivitis)
SIGNS AND SYMPTOMS
Pharyngoconjunc-tival fever (PCF) is characterized by fever, sore throat and follicular conjunctivitis. It may be unilateral or bilateral. It is caused regularly by adenovirus 3 and occasionally 4 or 7. Corneal infiltrates are rare. The disorder varies in severity but usually persists for four days to two weeks. While the virus is shed from the conjunctiva within 14 days, it remains in fecal matter for 30 days.
Epidemic Keratoconjunctivitis (EKC) often presents as a bilateral, inferior, palpebral, follicular conjunctivitis, with epithelial and stromal keratitis. Subepithelial corneal infiltrates are much more common in EKC than in PCF and are typically concentrated in the central cornea. EKC is regularly caused by adenovirus types 8 and 19.
The key clinical signs of both conditions include: conjunctival injection, tearing, serous discharge, edematous eyelids, pinpoint subconjunctival hemorrhages, pseudomembrane formation and palpable preauricular lymph nodes. In severe cases, conjunctival desiccation causes scarring and symblepharon formation (adherence of the bulbar and palpebral conjunctivas).
Both conditions are highly contagious. Patients will usually report recent contact with someone who had either red eyes or an upper respiratory infection. Both forms tend to start in one eye, then spread to the other eye within a few days. In rare cases, the focal subconjunctival hemorrhages can evolve into acute hemorrhagic conjunctivitis.
Adenovirus type 8 can proliferate in the corneal epithelial tissues, producing the characteristic keratitis and subepithelial infiltrates. This, along with the immune response to viral antigens, causes lymphocytes to collect in the shallow anterior stroma, just beneath the epithelium. Sometimes, a conjunctival membrane will form. These are made up of fibrin and leukocytes, and in prolonged cases, of fibroblast and collagen deposits. Pseudomembranes are much easier to remove than true membranes.
Medical management can range from cold compresses and artificial tears to topical vasoconstrictors (e.g., naphazoline) and steroids (Vexol, Flarex, Pred Forte) two to four times daily. If a membrane is present, peel it off with a wet, cotton-tipped applicator or forceps. After removal, prescribe a topical antibiotic-steroid combination such as Tobradex or Maxitrol q.i.d. Anti-viral drugs such as Viroptic are ineffective against adenovirus.
Recently, there has been a breakthrough in the management of adenoviral keratoconjunctivitis. Cidofovir (Vistide), an anti-viral drug used intravenously to treat cytomegalovirus retinitis, appears to be effective in adenoviral keratoconjunctivitis. The topical form creates a faulty viral DNA structure. Twice daily instillation is recommended. This topical anti-viral is also possibly effective against herpes simplex and zoster, and Epstein-Barr virus.
Eyelids & Eyelashes | Conjunctiva & Sclera | Cornea
Uvea | Vitreous & Retina | Optic Nerve & Brain | Oculosystemic Disease
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