—After the cure of sporotrichosis, a sporotrichin test was studied by A. Padilha Gonçalves and co-workers at the Institute of Tropical Medicine of São Paulo. The sporotrichin intradermic test was performed on 49 sporotrichotic patients clinically cured for periods from 1 mo to 12 yr. It was positive in 47 and negative in 2 patients. In comparison with the tests performed on those patients before treatment, the reactivity degree may be the same or may increase or decrease after cure. It was found that, as a rule, the sporotrichin intradermic test remains positive after the extinction of the activity of sporotrichosis. Thus the positive tests observed in persons without sporotrichosis should not be considered false-positive tests, since they probably indicate a previous unknown sporotrichotic infection healed spontaneously or as a consequence of treatment prescribed for other diseases.
—I. P. d'Alcântara Gomes de Souza, et al (Anais Santa
BRAZIL. JAMA. 1963;184(4):318. doi:10.1001/jama.1963.03700170110020