Sepsis: This condition is characterized by a systemic inflammatory response to infection, which can lead to elevated white blood cell (WBC) counts and increased lactic acid levels due to tissue hypoxia and metabolic derangements. The combination of elevated WBC and significantly elevated lactic acid is highly suggestive of sepsis.

Severe Infection: Similar to sepsis, severe infections can cause an elevation in WBC count as the body responds to the infectious agent. Elevated lactic acid can occur due to the infection itself or due to complications such as abscesses or necrotic tissue.
Acute Respiratory Distress Syndrome (ARDS): While primarily a respiratory condition, ARDS can lead to hypoxia, which in turn can cause lactic acidosis. An elevated WBC count can be seen in response to the underlying cause of ARDS or as a result of the syndrome itself.
Severe Dehydration: Dehydration can lead to lactic acidosis due to decreased perfusion of tissues. An elevated WBC count might be seen if the dehydration is secondary to an infectious process or if there is a systemic inflammatory response.

Mesenteric Ischemia: This is a condition where there is a lack of blood flow to the intestines, which can lead to tissue death. It presents with severe abdominal pain, elevated WBC count, and lactic acidosis. Missing this diagnosis can be fatal.
Toxic Shock Syndrome: Characterized by fever, rash, desquamation, hypotension, and involvement of three or more organ systems, toxic shock syndrome can present with elevated WBC and lactic acid levels. It is life-threatening and requires prompt recognition and treatment.
Meningitis or Encephalitis: Infections of the central nervous system can present with elevated WBC in the cerebrospinal fluid and systemic signs of infection, including elevated peripheral WBC count and lactic acidosis in severe cases.

Leukemia: Certain types of leukemia can present with extremely elevated WBC counts. While lactic acidosis is less common, it can occur, especially in the context of tumor lysis syndrome.
Mitochondrial Disorders: These are a group of disorders that affect the mitochondria, leading to impaired energy production. They can present with lactic acidosis and may have elevated WBC counts during episodes of illness.
D-Lactic Acidosis: A rare condition usually seen in patients with short bowel syndrome, where the fermentation of carbohydrates by colonic bacteria produces D-lactate, leading to acidosis. It might not always present with an elevated WBC count but is an important consideration in the right clinical context.