Wasp Sting in Child With Congenital Severe Neutropenia
A 10-year-old boy, with a diagnosis of congenital severe neutropenia with neutrophil levels below 0.5 for a majority of time, requiring granulocyte colony-stimulating factor (G-CSF) for cover during infective episodes, experienced wasp stings on 2 separate occasions. On both occasions his neutrophil count went up to 6.0 and remained there for 2 weeks before dropping. Previously, his neutrophil never went above 3.5, even with G-CSF, which also occurred in the first week only. I would like to know if anyone else has had a similar experience, and if so, what is the possible reason?

Anil Tuladhar, MBBS, MRCP(UK), MRCPCH

This is really a fascinating story. Although I have been unable to find a similar case in the literature, I would like to suggest a potential mechanism for this observation. Clearly, a wasp sting is a painful and stressful event, and the stress response, together with the acute inflammatory response induced by the sting, is likely to lead to the generation of a number of cytokines, growth factors, and hormones that could have stimulatory effects on the bone marrow. Although G-CSF can clearly exert this type of effect, a number of other cytokines, including stem cell factor, granulocyte-macrophage colony stimulating factor, and interleukins-3, -7, and -8, also boost various stages of granulocytopoiesis and neutrophil differentiation. One possibility is that the wasp stings boosted the synthesis of some or all of these factors, and that this led to the transient increase in circulating cells.