Parapsoriasis refers to one of a group of skin disorders that are characterized primarily by their resemblance to psoriasis (red, scaly lesions). Parapsoriasis is a rare cutaneous lymphoproliferative dermatoses that occurs mainly in middle-aged adults, 2/3 of which are male.

Skin cancer may be developed from parapsoriasis. For example, it can develop into cutaneous T-cell lymphoma.

Diagnosis and Treatment
Blood tests to rule out syphilis
Biopsy to rule out cutaneous lymphomas

      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.