Abstract
Case: A 7-month-old female infant presented with widespread brown macules that resulted in the development of erythema and urticarial wheals upon scratching. She was initially diagnosed with maculopapular mastocytosis, but the diagnosis was revised to diffuse cutaneous mastocytosis (DCM) due to the development of blisters and erosions on the brown macules. Histopathological examination showed elevated mast cell number in the upper dermis, and immunohistochemical staining for c-kit was positive, confirming the diagnosis.
Mast cells are known to release various mediators, including histamine, leukotrienes, and platelet-activating factor, which contribute to the inflammatory response and cutaneous symptoms of mastocytosis. Despite initial treatment with H1 antagonists (levocetirizine and chlorpheniramine), blister formation persisted. The leukotriene receptor antagonist pranlukast was subsequently introduced in addition to the H1 antagonists. This combination effectively suppressed blister formation, leading to rapid healing of the skin lesions.
The addition of pranlukast, a leukotriene receptor antagonist, to conventional H1 antagonist therapy effectively reduced blister formation in this case of DCM. These results suggest that targeting leukotriene pathways, in combination with histamine blockade, represent a promising therapeutic approach for managing refractory DCM.
