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.