Autoimmune lymphoproliferative syndrome is a disorder due to a defect of lymphocyte apoptosis, whose clinical manifestations consist of hyperplasia of lymphoid tissues and autoimmune diseases. We report on a 26-month-old child who presented with frequent eruptions of weals and angioedema without any apparent triggering factor, who subsequently developed an erythematopapular rash with a histological pattern of a lymphoplasmacellular infiltrate. Familial anamnesis revealed a history of lymphoadenomegaly and massive spleen and liver enlargement in her sister. Functional and molecular analysis led to a diagnosis of type 1a autoimmune lymphoproliferative syndrome. Immunophenotyping of the cutaneous lesion revealed the presence of an inflammatory infiltrate with a considerably high number of Langerhans cells. Cutaneous features such as urticaria, angioedema and vasculitis in children with a personal and familial history of hyperplasia of lymphoid tissues may be a presenting sign of a systemic disease, such as autoimmune lymphoproliferative syndrome.