Abt-Letterer-Siwi disease

  • Children <2yo (variable)
  • Skin 80% of cases, usually initial sign
    • Red-brown papules on ears, scalp, intertriginous
    • Resembles hemorrhagic seborrheic dermatitis, involves skin folds (~candida)
  • Often systemic involvement, acutely ill
    • Lymphadenopathy, hepatosplenomegaly, anemia, thrombocytopenia, fever, pulmonary and neurologic symptoms
    • Bone lesions rarer than other LCH, mastoid possible in all forms
  • Mortality >50%, worse prognosis if poor response to initial therapy