title: Indolent systemic mastocytosis treated with narrow-band UVB phototherapy: study of five cases.
abstract: BACKGROUND
  Mastocytoses represent a heterogeneous group of stem cell disorders marked by an abnormal hyperplasia and accumulation of mast cells in one or more tissues, including bone marrow, gastrointestinal tract, liver, spleen, lymph nodes and skin. Indolent systemic mastocytosis (ISM) is characterized by red-brownish and pruriginous maculopapular lesions, a bone marrow infiltration without functional impairment and an indolent clinical course with a good prognosis. In particular, the most common cutaneous symptoms are urticarial rash and mild-to-high pruritus.
  
  
  OBJECTIVE
  This study analyses the clinical outcome of patients affected by ISM with prevalent pruriginous cutaneous symptoms and a scarce response to anti-histamines treated using narrowband ultraviolet B (NB-UVB) phototherapy.
  
  
  METHODS
  Narrowband ultraviolet B phototherapy was administered in a UV-irradiation cabin equipped with fluorescent UVB lamps with a peak emission at 311-313 nm. The perception of pruritus severity was assessed using the Visual Analogue Scale (VAS) before starting the treatment and at each control.
  
  
  RESULTS
  A complete remission of the cutaneous lesions and pruritus was documented in all patients after a median of 40.3 UV treatments and a median cumulative dose of 51.4 J/cm(2), with a lasting remission over a 6-month follow-up. The median VAS score at the beginning of the treatment was 86.6 (SD=6.64), whereas it decreased to 6.66 (SD=3.75) after 3 months of therapy.
  
  
  CONCLUSIONS
  Our work provides evidence that NB-UVB phototherapy is useful for the treatment of the cutaneous symptoms and pruritus in ISM.
authors.affiliation: Department of Human and Hereditary Pathology, Institute of Dermatology, University of Pavia and Foundation IRCCS Policlinico San Matteo, Pavia, Italy. vbrazzelli@libero.it
authors.forename: V
authors.initials: V
authors.lastname: Brazzelli
authors.forename: V
authors.initials: V
authors.lastname: Grasso
authors.forename: G
authors.initials: G
authors.lastname: Manna
authors.forename: V
authors.initials: V
authors.lastname: Barbaccia
authors.forename: S
authors.initials: S
authors.lastname: Merante
authors.forename: E
authors.initials: E
authors.lastname: Boveri
authors.forename: G
authors.initials: G
authors.lastname: Borroni
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D034721:Mastocytosis, Systemic / Q000532:radiotherapy*; D008875:Middle Aged; D012871:Skin Diseases / Q000532:radiotherapy*; D014467:Ultraviolet Therapy / Q000379:methods*