Some disease entities have such a characteristic and striking appearance that their written descriptions are unmistakable. One such disease is serpiginous choroiditis, an idiopathic choroiditis that was given its name in 1970 by Gass,1 who had described the disease earlier in 1967.2 It is an acute and chronically recurrent inflammation of the inner half of the choroid and retinal pigment epithelium that secondarily affects the retina. It typically starts in the peripapillary region and spreads centrifugally over months to years in episodes of inflammation that arise from the edge of previously involved choroid. The term serpiginous, which has been used extensively in the vocabulary of dermatology, was used by Gass to describe the apparently serpentine, creeping pattern of progressive pathologic changes of the fundus, as it was thought initially that the disease crept with a snake-like pattern at varying speeds from the peripapillary region. While we now know that the long-term pattern of progressive elongation of the large, irregularly shaped lesions are caused by recurrent episodes of inflammation with very little creeping of the lesions, the serpiginous appearance could not be denied, and the name has remained.
Wenick AS, Odel JG. Serpiginous Choroiditis by Any Other Name. Arch Ophthalmol. 2005;123(11):1616-1618. doi:10.1001/archopht.123.11.1616