Causes of leukocytosis. (a)

Neutrophilic leukocytosis

Acute bacterial infections, especially those caused by pyogenic organisms;

sterile inflammation caused by, for example, tissue necrosis (myocardial infarction, burns)

Eosinophilic leukocytosis(eosinophilia)

Allergic disorders such as asthma, hay fever

allergic skin diseases (e.g., pemphigus, dermatitis herpetiformis)

parasitic infestations;

drug reactions;

certain malignancies (e.g., Hodgkin disease and some non-Hodgkin lymphomas);

collagen vascular disorders and some vasculitides;