case_images: PMC11803904_01
case_images: Two-year-old female on hospital day 3 with full-thickness desquamation and underlying erythema with surrounding tense bullae on the chest, back, and posterior neck, involving 20% body surface area (A and B).
case_images: gr1.jpg
case_images: PMC11803904_01_gr1.jpg
case_images: fig1
case_images: Skin examination on hospital day 3 revealed full-thickness desquamation with underlying erythema and surrounding tense bullae on the chest, back, and neck, involving 20% of the patient's body surface area (Fig 1).
case_images: Hematoxylin and eosin, 4x (A) and 40x (B). Subepidermal split with numerous monomorphic cells in the upper dermis, resembling mast cells. CD117 stain, 40x (C) highlights a proliferation of mast cells in the upper dermis, confirming the diagnosis of mastocytosis.
case_images: gr2.jpg
case_images: PMC11803904_01_gr2.jpg
case_images: fig2
case_images: Histology demonstrated a subepidermal blister with a dermal infiltrate of numerous round monomorphic cells (Fig 2). Immunohistochemical staining revealed expression of CD117 and tryptase (Fig 2), confirming mast cell lineage, and rendering the diagnosis of BM.