Conjunctivitis due to Phthirus pubis: a trap for the unwary.

It is not uncommon for patients to present to eye casualties with a red eye and where treatment has already been started by the general practitioner, usually in the form of antibiotic drops or ointment for presumed bacterial/viral conjunctivitis. Occasionally, the diagnosis is not simply a bacterial conjunctivitis and this can only be clarified by close ocular inspection.