I would like to comment on the recent articles by Ackerman and Schiff1 and Burg et al,2 which attempt to clarify the clinical significance of small plaque parapsoriasis (SPP). The clinician is occasionally faced with a patient whose skin eruption cannot be readily distinguished between SPP and early mycosis fungoides (MF) based on clinical and histopathological grounds. Burg et al use the reasoning that if, over time, the patient develops classic MF, then the earlier eruption was clearly MF and never SPP. They make the related statement that SPP eruptions never progress to MF, thus clearly distinguishing SPP from MF.
However, this is circular logic; SPP cannot be MF, if part of the definition of SPP is that it does not evolve into MF. If one cannot clinically or pathologically distinguish SPP from early MF, what transpires in the future (stability vs MF) cannot be used to prove
Raskin CA. Small Plaque Parapsoriasis and Mycosis Fungoides. Arch Dermatol. 1996;132(11):1388. doi:10.1001/archderm.1996.03890350132026