Parapsoriasis

This code represents a group of chronic inflammatory skin conditions characterized by scaly, erythematous patches that clinically resemble psoriasis but lack its typical histopathological features. These conditions are often categorized as small plaque parapsoriasis (benign) or large plaque parapsoriasis, the latter having a potential for progression to cutaneous T-cell lymphoma (CTCL).

Use this code for documented diagnoses of parapsoriasis, including both small plaque and large plaque variants, when the specific type of parapsoriasis is not further specified by the provider. Documentation should clearly indicate a diagnosis of parapsoriasis, often following a biopsy that differentiates it from true psoriasis or other dermatoses.

• Differentiate from true psoriasis (696.1x) based on clinical and histopathological findings.
• If large plaque parapsoriasis progresses to mycosis fungoides (a type of CTCL), code the CTCL instead.
• Ensure documentation specifies "parapsoriasis" rather than just "psoriasis" to avoid coding errors.