Mastocytosis refers to a rare collection of disorders, both cutaneous and systemic, that are characterized by increased numbers of mast cells. Depending on the extent of the disease, these disorders may present with symptoms resulting from mast cell degranulation including flushing, diarrhea, vomiting, cramping, syncope, or anaphylaxis. In pediatric patients, cutaneous involvement is most prevalent in the form of urticaria pigmentosa, which is typically asymptomatic or minimally so with resolution by adolescence. In this case report and review of literature, we review a case of a 3-year-old child with uritcaria pigmentosa displaying recurrent syncope and anaphylaxis as the first presentation of systemic mastocytosis. We found data to be limited on this topic, and concluded that pediatric patients with prior diagnoses of cutaneous mastocytosis could benefit from either more aggressive screening for systemic disease or prophylactic treatment with antihistamines and rescue subcutaneous epinephrine.