18 Hidden Causes of High Neutrophil Counts That Doctors Want You to Know

18. Allergic Reactions and Anaphylaxis

While allergies are typically associated with an increase in eosinophils (another type of white blood cell), severe allergic reactions can also trigger neutrophilia. During an allergic response, the immune system releases histamines and inflammatory cytokines, leading to increased production and mobilization of neutrophils. In cases of anaphylaxis, a life-threatening allergic reaction, neutrophils may be rapidly deployed to help counteract widespread inflammation and tissue damage. Additionally, chronic allergic conditions such as allergic asthma and hay fever can contribute to mild, persistent neutrophilia due to ongoing immune activation. Understanding how allergic responses influence white blood cell levels can help individuals manage their symptoms more effectively and seek appropriate treatment when necessary.