3.3.11 Parapsoriasis-Group

Xanthoerythroderma perstans

Digitate dermatosis

Atrophic parapsoriasis

Poikilodermatous parapsoriasi

Parapsoriasis is a group of diseases characterized by the presence of scaling macules or patches that can resemble psoriatic lesions. Its importance comes from the fact that some cases can represent (or transform into) cutaneous T-cell lymphomas.

Subtle eczematous changes of the epidermis with a few lymphocytes in the dermis and the epidermis. No band like infiltrate in the papilary dermis. No lymphocyte microabscesses in the epidermis. Atrophy of the epidermis and poikilodermia (hyper- and depigmentation) in PAV.Subtle eczematous changes of the epidermis with a few lymphocytes in the dermis and the epidermis. No band like infiltrate in the papilary dermis. No lymphocyte microabscesses in the epidermis. Atrophy of the epidermis and poikilodermia (hyper- and depigmentation) in PAV.

Chronic over years or decades. Follow-up mandatory because of potential development of mycosis fungoides. Multiple biopsies should be taken during the course of the disease.

LPP and PAV may develop to CTCL, preferentially mycosis fungoides (within years or decades). Some cases represent patients that are in fact mycosis fungoides but we do not have enough clinical-pathologic-molecular criteria to confirm the diagnosis of lymphoma.

Atopic or seborrheic eczema, CTCL subtypes in particular mycosis fungoides, tinea corporis, pityriasis versicolor, pithyriasis rosea.

Prevention not possible. Topical therapy: photo-(helio-) or photochemotherapy. Glucocorticosteroid- cream temporarily. Topical calcineurin inhibitors.