Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Parapsoriasis (small plaque and large plaque parapsoriasis)

Laura Y McGirt, MD
Section Editor
John A Zic, MD
Deputy Editor
Rosamaria Corona, MD, DSc


The term "parapsoriasis" refers to a heterogeneous group of uncommon dermatoses occurring mainly in older adults and characterized by erythematous and scaly patches of variable size, chronic course, and resistance to treatment [1,2]. It is broadly divided in two main types: small plaque parapsoriasis (SPP) and large plaque parapsoriasis (LPP). In both types, lesions are typically asymptomatic or accompanied by mild pruritus and are predominantly located on the trunk. While SPP is generally considered a chronic benign condition, LPP is regarded as a premalignant dermatosis with a substantial risk of progression to mycosis fungoides, the most common type of cutaneous T cell lymphoma. (See "Clinical manifestations, pathologic features, and diagnosis of mycosis fungoides", section on 'Premycotic period'.)

SPP and LPP will be discussed in this topic. Other cutaneous lymphoproliferative disorders and mycosis fungoides are discussed separately.

(See "Pityriasis lichenoides chronica".)

(See "Pityriasis lichenoides et varioliformis acuta (PLEVA)".)

(See "Lymphomatoid papulosis".)


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Sep 2016. | This topic last updated: Oct 14, 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. Benmamán O, Sánchez JL. Comparative clinicopathological study on pityriasis lichenoides chronica and small plaque parapsoriasis. Am J Dermatopathol 1988; 10:189.
  2. Lambert WC, Everett MA. The nosology of parapsoriasis. J Am Acad Dermatol 1981; 5:373.
  3. Väkevä L, Sarna S, Vaalasti A, et al. A retrospective study of the probability of the evolution of parapsoriasis en plaques into mycosis fungoides. Acta Derm Venereol 2005; 85:318.
  4. Simon M, Flaig MJ, Kind P, et al. Large plaque parapsoriasis: clinical and genotypic correlations. J Cutan Pathol 2000; 27:57.
  5. Belousova IE, Vanecek T, Samtsov AV, et al. A patient with clinicopathologic features of small plaque parapsoriasis presenting later with plaque-stage mycosis fungoides: report of a case and comparative retrospective study of 27 cases of "nonprogressive" small plaque parapsoriasis. J Am Acad Dermatol 2008; 59:474.
  6. Kikuchi A, Naka W, Harada T, et al. Parapsoriasis en plaques: its potential for progression to malignant lymphoma. J Am Acad Dermatol 1993; 29:419.
  7. Haeffner AC, Smoller BR, Zepter K, Wood GS. Differentiation and clonality of lesional lymphocytes in small plaque parapsoriasis. Arch Dermatol 1995; 131:321.
  8. Klemke CD, Dippel E, Dembinski A, et al. Clonal T cell receptor gamma-chain gene rearrangement by PCR-based GeneScan analysis in the skin and blood of patients with parapsoriasis and early-stage mycosis fungoides. J Pathol 2002; 197:348.
  9. Pimpinelli N, Olsen EA, Santucci M, et al. Defining early mycosis fungoides. J Am Acad Dermatol 2005; 53:1053.
  10. Leloup P, Nguyen JM, Quéreux G, et al. Predictive value of T-cell clone and CD13 antigen in parapsoriasis. J Eur Acad Dermatol Venereol 2014; 28:518.
  11. Erkek E, Sahin S, Atakan N, et al. Absence of Epstein-Barr virus and human herpesvirus-6 in pityriasis lichenoides and plaque parapsoriasis. J Eur Acad Dermatol Venereol 2002; 16:536.
  12. Ballanger F, Bressollette C, Volteau C, et al. Cytomegalovirus: its potential role in the development of cutaneous T-cell lymphoma. Exp Dermatol 2009; 18:574.
  13. Amitay-Laish I, Sarid R, Ben-Amitai D, et al. Human herpesvirus 8 is not detectable in lesions of large plaque parapsoriasis, and in early-stage sporadic, familial, and juvenile cases of mycosis fungoides. J Am Acad Dermatol 2012; 66:46.
  14. Quéreux G, André-Garnier E, Knol AC, et al. Evaluation of the role of human herpes virus 6 and 8 in parapsoriasis. Exp Dermatol 2009; 18:357.
  15. Kreuter A, Bischoff S, Skrygan M, et al. High association of human herpesvirus 8 in large-plaque parapsoriasis and mycosis fungoides. Arch Dermatol 2008; 144:1011.
  16. Trento E, Castilletti C, Ferraro C, et al. Human herpesvirus 8 infection in patients with cutaneous lymphoproliferative diseases. Arch Dermatol 2005; 141:1235.
  17. Weedon D. Skin Pathology, 2nd ed, Churchill Livingstone, St. Louis 2002.
  18. Ross S, Sánchez JL. Parapsoriasis. A century later. Int J Dermatol 1990; 29:329.
  19. Wood GS, Reizner G. Other papulosquamous disorders. In: Dermatology, 2nd ed, Bolognia JL, Jorizzo JL, Rapini RP (Eds), Elsevier, Spain 2008. Vol 1.
  20. Wood GS, Hu CH, Liu R. Parapsoriasis and pityriasis lichenoides. In: Fitzpatrick's Dermatology in General Medicine, 8th ed, Goldsmith LA, Katz SI, Gilchrest BA, Paller AS (Eds), McGraw-Hill Medical, New York 2012. Vol 1.
  21. Zackheim HS, Kashani-Sabet M, Amin S. Topical corticosteroids for mycosis fungoides. Experience in 79 patients. Arch Dermatol 1998; 134:949.
  22. Zackheim HS. Treatment of patch-stage mycosis fungoides with topical corticosteroids. Dermatol Ther 2003; 16:283.
  23. Takahashi H, Takahashi I, Tsuji H, et al. Digitate dermatosis successfully treated by narrowband ultraviolet B irradiation. J Dermatol 2011; 38:923.
  24. Aydogan K, Karadogan SK, Tunali S, et al. Narrowband UVB phototherapy for small plaque parapsoriasis. J Eur Acad Dermatol Venereol 2006; 20:573.
  25. Herzinger T, Degitz K, Plewig G, Röcken M. Treatment of small plaque parapsoriasis with narrow-band (311 nm) ultraviolet B: a retrospective study. Clin Exp Dermatol 2005; 30:379.
  26. Hofer A, Cerroni L, Kerl H, Wolf P. Narrowband (311-nm) UV-B therapy for small plaque parapsoriasis and early-stage mycosis fungoides. Arch Dermatol 1999; 135:1377.
  27. Arai R, Horiguchi Y. Retrospective study of 24 patients with large or small plaque parapsoriasis treated with ultraviolet B therapy. J Dermatol 2012; 39:674.
  28. Duarte IA, Korkes KL, Amorim VA, et al. An evaluation of the treatment of parapsoriasis with phototherapy. An Bras Dermatol 2013; 88:306.
  29. Murphy M, Fullen D, Carlson JA. Low CD7 expression in benign and malignant cutaneous lymphocytic infiltrates: experience with an antibody reactive with paraffin-embedded tissue. Am J Dermatopathol 2002; 24:6.
  30. Alaibac M, Pigozzi B, Belloni-Fortina A, et al. CD7 expression in reactive and malignant human skin T-lymphocytes. Anticancer Res 2003; 23:2707.
  31. Florell SR, Cessna M, Lundell RB, et al. Usefulness (or lack thereof) of immunophenotyping in atypical cutaneous T-cell infiltrates. Am J Clin Pathol 2006; 125:727.
  32. Pigozzi B, Bordignon M, Belloni Fortina A, et al. Expression of the CD1a molecule in B- and T-lymphoproliferative skin conditions. Oncol Rep 2006; 15:347.
  33. Zeybek ND, Asan E, Erbil AH, Dagdeviren A. Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells. Acta Histochem 2008; 110:380.
  34. McGirt LY, Degesys CA, Johnson VE, et al. TOX expression and role in CTCL. J Eur Acad Dermatol Venereol 2016; 30:1497.
  35. Olsen E, Vonderheid E, Pimpinelli N, et al. Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC). Blood 2007; 110:1713.
  36. Powell FC, Spiegel GT, Muller SA. Treatment of parapsoriasis and mycosis fungoides: the role of psoralen and long-wave ultraviolet light A (PUVA). Mayo Clin Proc 1984; 59:538.
  37. Rosenbaum MM, Roenigk HH Jr, Caro WA, Esker A. Photochemotherapy in cutaneous T cell lymphoma and parapsoriasis en plaques. Long-term follow-up in forty-three patients. J Am Acad Dermatol 1985; 13:613.
  38. Weberschock T, Strametz R, Lorenz M, et al. Interventions for mycosis fungoides. Cochrane Database Syst Rev 2012; :CD008946.
  39. Lindahl LM, Fenger-Gron M, Iversen L. Topical nitrogen mustard therapy in patients with mycosis fungoides or parapsoriasis. J Eur Acad Dermatol Venereol 2013; 27:163.
  40. Zackheim HS, Epstein EH Jr, McNutt NS, et al. Topical carmustine (BCNU) for mycosis fungoides and related disorders: a 10-year experience. J Am Acad Dermatol 1983; 9:363.
  41. Lazar AP, Caro WA, Roenigk HH Jr, Pinski KS. Parapsoriasis and mycosis fungoides: the Northwestern University experience, 1970 to 1985. J Am Acad Dermatol 1989; 21:919.
  42. Lindahl LM, Fenger-Grøn M, Iversen L. Subsequent cancers, mortality, and causes of death in patients with mycosis fungoides and parapsoriasis: a Danish nationwide, population-based cohort study. J Am Acad Dermatol 2014; 71:529.
  43. Sibbald C, Pope E. Systematic review of cases of cutaneous T-cell lymphoma transformation in pityriasis lichenoides and small plaque parapsoriasis. Br J Dermatol 2016; 175:807.