title: Large maculopapular cutaneous lesions are associated with favorable outcome in childhood-onset mastocytosis.
abstract: BACKGROUND
  Mastocytosis, characterized by pathologic accumulation of mast cells, can manifest itself in adulthood or childhood. Pediatric patients usually have cutaneous mastocytosis (CM) with mast cell infiltrates limited to the skin and spontaneous improvement of skin lesions after several years. However, there are some patients with persistent disease resembling adulthood-onset mastocytosis.
  
  
  OBJECTIVE
  The current classification of CM differentiates between 3 subforms. In clinical practice we noticed that different variants of these subforms might exist, particularly in patients with childhood-onset mastocytosis. Therefore, in the present study, we aimed to investigate whether specific cutaneous lesions in patients with childhood-onset mastocytosis are associated with other disease parameters.
  
  
  METHODS
  We analyzed 144 patients with a disease onset of less than age 17 years using a systematic dermatologic approach.
  
  
  RESULTS
  One hundred twenty-two patients presented with maculopapular cutaneous mastocytosis (MPCM), 12 patients presented with diffuse CM, and 10 patients presented with solitary mastocytoma of the skin. Patients with MPCM showed particularly heterogeneous cutaneous lesions and were therefore grouped into 3 variants presenting either with small lesions (MPCM-small, skin lesions <1 cm in diameter; n = 19), large lesions (MPCM-large, skin lesions ≥ 1 cm in diameter; n = 89), or atypical lesions (MPCM-other, n = 14). Patients with MPCM-large lesions, compared with those with MPCM-small lesions, were characterized by significantly lower tryptase levels, shorter disease duration, and earlier disease onset. In addition, more patients with MPCM-large lesions exhibited spontaneous regression of cutaneous lesions.
  
  
  CONCLUSIONS
  Our data show that patients with MPCM-large lesions compared with those with MPCM-small lesions have a more favorable disease course and suggest exploring the size of cutaneous lesions as a prognostic parameter in childhood-onset MPCM.
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Wiechers
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Rabenhorst
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany; Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Schick
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Liane M
authors.initials: LM
authors.lastname: Preussner
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Förster
authors.affiliation: Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Valent
authors.affiliation: Institute of Pathology, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Horny
authors.affiliation: Institute of Pathology, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Sotlar
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany; Department of Dermatology, University of Luebeck, Luebeck, Germany. Electronic address: karin.hartmann@uksh.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Hartmann
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D053802:Tryptases / Q000097:blood; D014582:Urticaria Pigmentosa / Q000097:blood / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D055815:Young Adult
chemical_list: D019009:Proto-Oncogene Proteins c-kit; D053802:Tryptases
keywords: Childhood-onset mastocytosis; KIT mutation; cutaneous mastocytosis; mast cell; mastocytosis; pediatric mastocytosis; prognosis; skin; tryptase; urticaria pigmentosa