There continues to be debate over the definition and existence of large plaque parapsoriasis (LPP). The term was used historically to designate what was thought to be a chronic inflammatory eruption seen most often in middle-aged and elderly patients, slightly more frequently in men. In older literature 10%-30% of these cases were shown to progress to mycosis fungoides (MF), and so LPP was conceptualized as the inflammatory precursor to MF.

Given that LPP plaques resemble patch stage MF clinically but lack the criteria for the diagnosis of mycosis fungoides histopathologically, many contemporary experts conceptualize LPP to be the same as early patch stage MF and do not employ the term LPP at all. Others, however, do continue to diagnose LPP until the full histopathologic picture of mycosis fungoides is present.

Related topics: Mycosis Fungoides, Small Plaque Parapsoriasis