Redness of the conjunctiva.
Depends on the organism.
Viral: Epidemic keratoconjunctivitis: most commonly Adenovirus serotype 8 and others; Enterovirus 70 causes hemorrhagic conjunctivitis; as well as Coxsackievirus and Adenovirus.
Every class of organism can infect the conjunctiva so history and cultures are important.
Usually an antibiotic eye drop for 10 days: quinolone and aminoglycosides both come in eye drops, which one you use makes little difference.
ICD9 Codes (Soon to be supplanted by ICD10)
Conjunctivitis NEC 372.30; acute hemorrhagic 077.4; adenoviral (acute) 077.3; allergic (chronic) 372.14; chlamydial 077.98; filariasis 125.9 ; hemorrhagic (acute) (epidemic) 077.4; herpetic (simplex) 054.43; influenzal 372.03; mucocutaneous leishmaniasis 085.5 ; parasitic 372.15; purulent 372.03; Reiter's disease 099.3 ; syphilis 095.8 ; toxoplasmosis (acquired) 130.1, congenital (active) 771.2; tuberculous 017.3 ; tularemic 021.3; viral 077.99; zoster 053.21.