Mastocytosis

From IDWiki

Clinical Manifestations

Indolent Systemic Mastocytosis

  • Most common cause of adult-onset mastocytosis
  • Usually associated with small monomorphic maculopapular lesions on thigh or trunk
  • Anaphylaxis in 50%

Urticaria Pigmentosa

  • Presents with maculopapular rash that can resemble freckles
  • Usually has systemic involvement
  • Darier's sign: light rubbing or scratching of a lesion will cause erythema or urticaria

Unexplained or Severe Anaphylaxis

  • Anaphylaxis, usually without urticaria or angioedema
  • Without a trigger, or in response to bee/wasp/etc sting

Other Syndromes

  • Adult with hematologic abnormalities, splenomegaly, and weight loss

Investigations

  • CBC may show cyptopenias or cytoses, including eosinophilia and circulating mast cells
  • Serum tryptase, at baseline (not during an attack), which should be elevated
  • Liver enzymes for possible liver involvement
  • Bone dexa for osteopenia or osteoporosis