Parapsoriasis - 類乾癬
類乾癬 (Parapsoriasis) は、主に乾癬 (赤色の鱗状の病変) に似ていることを特徴とする皮膚疾患群の 1 つを指します。類乾癬は、主に中年の成人に発生する稀な皮膚リンパ増殖性皮膚炎で、そのうち 2/3 が男性です。

類乾癬 (parapsoriasis) から皮膚がんが発生する可能性があります。たとえば、皮膚 T 細胞リンパ腫に発展する可能性があります。


      References Parapsoriasis-A Diagnosis with an Identity Crisis: A Narrative Review 35426607 
      Parapsoriasis is an uncommon inflammatory skin disease characterized by chronic patches that may be resistant to therapy. It was primarily introduced and classified 120 years ago, and the original classification incorporated parapsoriasis and pityriasis lichenoides under the umbrella term parapsoriasis. After a major change in classification, parapsoriasis now exclusively refers to small plaque parapsoriasis (SPP) and large plaque parapsoriasis (LPP). However, debates still frequently occur regarding various nomenclatures and classifications used by different authors. Moreover, parapsoriasis may progress to overt cutaneous lymphoma, most commonly mycosis fungoides (MF), and it is very difficult to distinguish these two conditions despite modern histologic and molecular testing techniques.
       Histopathologic Evaluation of Parapsoriasis from the Perspective of NB-UVB/PUVA Therapy on the Outcome and Recurrence of the Disease 33911303 
      Parapsoriasis, presented as an early stage of cutaneous T-cell lymphoma, is mostly treated with psoralen and ultraviolet A (PUVA) therapy and narrowband ultraviolet B (NB-UVB) phototherapy.