TY - CHAP M1 - Book, Section TI - Mastocytosis A1 - Tharp, Michael D. A2 - Kang, Sewon A2 - Amagai, Masayuki A2 - Bruckner, Anna L. A2 - Enk, Alexander H. A2 - Margolis, David J. A2 - McMichael, Amy J. A2 - Orringer, Jeffrey S. PY - 2019 T2 - Fitzpatrick's Dermatology, 9e AB - AT-A-GLANCEMASTOCYTOSISThe hallmark of mastocytosis is a pathologic accumulation of mast cells in tissues.Mastocytosis occurs at any age but children are more commonly affected.Cutaneous findings consist of hyperpigmented macules, papules, or nodules, or a diffuse infiltration of the dermis.Most children only have skin involvement, whereas adults are more likely to have systemic disease.Mastocytosis is usually associated with somatic activating mutations of c-kit with the 816 codon mutation being most common.Many patients have few, if any, symptoms, but some experience varying degrees of flushing, pruritus, hypotension, nausea, dyspepsia, and diarrhea.Most common extracutaneous tissues involved are the bone marrow, liver, spleen, and lymph nodes.Some patients may develop an associated myeloproliferative or myelodysplastic disorder.No effective cure currently exists; treatment is focused on controlling symptomsMAST CELLSMast cells are derived from pluripotent stem cells.Stem cell factor is the ligand for KIT and is required for mast cell proliferation and survival.Mast cells release both preformed and newly generated mediators. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1161329981 ER -