Cutaneous mastocytosis: pediatric approach to solitary mastocytoma

Cutaneous mastocytosis is an uncommon disease characterized by clonal mast cell proliferation limited to the skin, predominantly affecting pediatric patients. Solitary mastocytoma is the second most frequent variant and usually follows a benign, self-limited course, making clinical recognition essential to avoid unnecessary invasive studies. A 1-year-and-6-month-old previously healthy female patient presented with a single lumbar skin lesion appearing during early infancy. The lesion was an erythematous-brown macule-plaque with friction-induced blistering and a positive Darier sign, without systemic symptoms. A clinical diagnosis of solitary mastocytoma was established. Treatment included topical corticosteroid, topical calcineurin inhibitor, and general measures, with favorable evolution. Pediatric solitary mastocytoma is infrequent, has early onset, and an excellent prognosis. Diagnosis is clinical and management conservative, allowing avoidance of unnecessary procedures and appropriate family counseling and long term follow up.