LCH is an aberrant monoclonal proliferation of dendritic cells, ranging from a self-limiting local condition to a rapidly progressive multisystemic disease. Pathogenic cells expressed, in almost 70% of cases, an activation of the MAPK/ERK signaling pathway, in particular BRAF V600E mutation. We report on a newborn with multisystemic disease diagnosed in life-threatening medical conditions, who was successfully treated with the early association of BRAF inhibitor Vemurafenib to chemotherapy. After 12 months, Vemurafenib was discontinued, without any signs of relapse. This case indicates that early combination of target therapy with standard treatment may induce rapid response and prolonged disease remission.

Cow's milk allergy non-responsive to amino acid-based formula must raise suspicion of Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome. This is a potentially fatal disease associated with food allergy, sometimes leading to diagnostic delay. In our case, early diagnosis and management provided life-saving therapy.