Histoplasmin skin tests and dilated funduscopic examination for presumed ocular histoplasmosis were carried out on 842 individuals, aged 13 years and older, from Walkersville, Md. Seventy percent of the male and 51% of the female population were sensitive to the histoplasmin skin test; among reactors, males had a mean diameter of induration of 11.6 mm, and females had a mean induration of 9.7 mm. Histoplasmin sensitivity was most frequent in the third to the sixth decade, and mean induration size was largest in the third to the fifth decade.
Twenty-one individuals were identified as having only peripheral atrophic scars of presumed ocular histoplasmosis. The frequency of these scars was 2.5% and was similar in both sexes and at all age groups. One case of a disciform lesion was identified by the survey, giving a prevalence of about 0.1% in the community and a prevalence of about 4.5% among those with peripheral atrophic scars. All cases of presumed ocular histoplasmosis were histoplasmin-positive; male cases had a mean induration of 15.0 mm, and female cases had an induration of 10.7 mm.
Ganley JP, Smith RE, Knox DL, Comstock GW. Presumed Ocular HistoplasmosisIII. Epidemiologic Characteristics of People With Peripheral Atrophic Scars. Arch Ophthalmol. 1973;89(2):116-119. doi:10.1001/archopht.1973.01000040118011