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Small plaque parapsoriasis
Other Resources UpToDate PubMed

Small plaque parapsoriasis

Contributors: Catherine Chung MD, Art Papier MD, Jeffrey D. Bernhard MD
Other Resources UpToDate PubMed


Small plaque parapsoriasis is a skin condition of unknown etiology that is part of a group of chronic, idiopathic dermatoses known as the parapsoriasis group, so-named for the presence of scaly plaques that clinically resemble psoriasis. Along with small plaque parapsoriasis, this group includes large plaque parapsoriasis, lymphomatoid papulosis, pityriasis lichenoides et variola acuta (PLEVA), and pityriasis lichenoides chronica (PLC). Controversy over the nosology of the "parapsoriasis" disorders has gone on for decades and shows no signs of remitting.

Small plaque parapsoriasis most commonly occurs in middle-aged adults and the elderly. The medical literature is replete with debate over the parapsoriasis group of dermatoses and their possible transformation into cutaneous T-cell lymphoma. The most recent World Health Organization classification of cutaneous lymphomas considers small plaque parapsoriasis a benign disease with no potential for transformation into lymphoma. In contrast, large plaque parapsoriasis is considered a premalignant lymphoproliferative disorder with potential for malignant transformation.

Parapsoriasis is typically asymptomatic or can be mildly pruritic. The itch may have a burning character. The course is indolent and typically chronic. Parapsoriasis can last for years.


L41.3 – Small plaque parapsoriasis

23854007 – Small plaque parapsoriasis

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Differential Diagnosis & Pitfalls

The most important diagnosis to consider is Cutaneous T-cell lymphoma (mycosis fungoides). Small, early lesions of mycosis fungoides can be difficult to distinguish clinically from small plaque parapsoriasis. Biopsy will differentiate between the two diagnoses.
  • Nummular dermatitis
  • Psoriasis
  • Pityriasis rosea
  • Exanthematous drug eruption, especially pityriasis rosea-like
  • Pityriasis lichenoides chronica
  • Secondary syphilis

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Last Updated:11/11/2021
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Small plaque parapsoriasis
A medical illustration showing key findings of Small plaque parapsoriasis : Erythema, Primarily truncal distribution, Fine scaly plaques
Clinical image of Small plaque parapsoriasis - imageId=322267. Click to open in gallery.  caption: 'A close-up of numerous thin, scaly, pink, and light brown papules and plaques.'
A close-up of numerous thin, scaly, pink, and light brown papules and plaques.
Copyright © 2024 VisualDx®. All rights reserved.