Notable increase of pediatric patients with idiopathic anaphylaxis (IA) has been noted in recent years. IA is a potentially life-threatening disease caused by an unknown trigger and it must be recognised and treated in a way that prevents fatal outcome. There have been no previous reports of IA with histamine intolerance (HI) in a pediatric patient. Possible connection of HI with IA needs further investigation. Positive autologous serum skin test (ASST) in our patients with IA yet with no proof of circulating auto antibodies against IgE and against subunit of the high-affinity IgE receptor suggests other possible autoantibodies causing autoreactivity. Thus, autoimmunity could be another, up to now not sufficiently investigated cause of IA.