Parinaud syndrome is an eye problem similar to conjunctivitis ("pink eye"). It usually affects only one eye and is accompanied by nearby swollen lymph nodes and an illness with a fever.
Many different infections can cause Parinaud syndrome, including bacteria, viruses, fungi and parasites.
The most common causes are tularemia (rabbit fever) and cat-scratch fever. Tularemia can infect the eye either by direct entry of the bacteria into the eye (on a finger or other object), or by air droplets that carry the bacteria, and then land on the eye. Other infectious diseases may spread by these mechanisms, or through the bloodstream to the eye.