Raised baseline serum concentrations of mast-cell tryptase and mastocytosis are potential risk factors for severe allergic reactions to Hymenoptera venom.

Anaphylactic reactions to honeybee and wasp stings (Hymenoptera stings) are common and vary in severity for reasons that are not clear. Systemic anaphylactic reactions are often accompanied by a temporary rise in tryptase concentrations that lasts for several hours. In 3 February Lancet Dagmar Ludolph-Hauser and colleagues from Ludwig-Maximilians University, Munich, Germany, investigate if there is a direct link between the severity of anaphylactic reactions to Hymenoptera stings and serum tryptase concentrations.

They studied 114 patients and found that nine (75%) of 12 patients with raised tryptase concentrations had a history of severe sting reactions. But only 28 (28%) of the 102 patients with lower tryptase concentrations had a similar history of severe sting reactions (p=0.004). Cutaneous mastocytosis was diagnosed in most cases (Lancet 2001,...