An acute dentoalveolar abscess most characteristically produces which change in the peripheral blood?

Correct answer: D. Leukocytosis with a neutrophil predominance

• A. Lymphocytosis is the pattern of VIRAL infections and of chronic infections such as tuberculosis, and of lymphoproliferative disease.
• B. Neutropenia (ANC below 1500/mm3) is a cause of severe oral infection and ulceration rather than a consequence of one; it demands haematologic evaluation before invasive care.
• C. Leukopenia signals marrow failure, overwhelming sepsis, or chemotherapy — and in a patient with a dental infection it is an ominous finding that warrants urgent medical referral.
• D. CORRECT. An acute PYOGENIC bacterial infection triggers demargination and accelerated release of neutrophils from the bone marrow, giving a raised total white cell count — LEUKOCYTOSIS — typically in the range of 12,000-20,000/mm3 with a NEUTROPHIL predominance and a 'left shift' (increased immature band forms). Neutrophils are the first responders to pyogenic bacteria and constitute the pus itself.

Note: Numbers worth carrying: normal WBC 4,000-11,000/mm3; ANC below 1500 = neutropenia; ANC below 500 = severe neutropenia with high risk of life-threatening infection, where elective dental treatment is deferred and antibiotic cover is arranged with the physician.