obsolete leukemoid reaction

A leukemoid reaction is an increase in the white blood cell count that can mimic leukemia, but it is actually a physiological response to stress or infection, not a sign of cancer [12]. This condition is characterized by an increased white blood cell count (> 50,000 cells/μL) and often includes immature cells such as myeloblasts or red blood cells with nuclei in the peripheral blood [13].

In the past, leukemoid reaction was considered to be a disease, but it is now understood that it is not a primary blood malignancy, such as leukemia. Instead, it is a response to an underlying condition, which can include infections, immune-mediated disorders, or other diseases [4]. Blood counts often return to normal when the underlying condition is treated [12].

A leukemoid reaction can be associated with various types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils [14]. It was first introduced by Krumbhaar in 1926 as a term to describe leukocytic features that could mimic leukemia [14].

It's worth noting that while leukemoid reaction is not a disease itself, it can be associated with other conditions, such as paraneoplastic syndromes. Paraneoplastic leukemoid reaction (PLR) is a type of leukemoid reaction that occurs in patients with solid tumors, especially those with pulmonary malignancy and metastatic disease [15].

Leukemoid Reaction: A Review of Signs and Symptoms

A leukemoid reaction, also known as a leukemoid response, is an increase in the white blood cell count that can mimic leukemia. However, it's essential to note that this condition has been largely considered obsolete due to advancements in medical understanding.

Historical Context In the past, a leukemoid reaction was characterized by a significant increase in mature neutrophils and a differential count showing marked left shift [1][2]. This condition was often associated with severe infections or acute exacerbations of chronic infections [3].

Clinical Features

• Fever: A common symptom of leukemoid reaction, fever can range from mild to severe [4].
• Skin Rash: Some patients may experience a skin rash as part of the leukemoid reaction [5].
• Lymphadenopathy: Enlarged lymph nodes were also reported in some cases [6].
• Hepatitis: Liver inflammation was another symptom associated with leukemoid reaction [7].

Differential Diagnosis

• Infection: Severe infections, such as c. diff, TB, or shigella, can cause a leukemoid reaction [8].
• Drugs/Toxins: Exposure to certain drugs or toxins, like corticosteroids or G-CSF, can also lead to this condition [9].

Current Understanding

While the term "leukemoid reaction" is still used in some medical contexts, it's essential to note that this condition has been largely replaced by more accurate diagnoses. Modern medicine recognizes that an elevated white blood cell count can be caused by various factors, including infections, inflammation, or exposure to certain substances.

References

[1] Achufusi, TGO (2020) - Characterized by a significant increase in mature neutrophils and a differential count showing marked left shift [1]. [2] Achufusi, TGO (2020) - Same as above. [3] Zeng, Q (2013) - This reaction typically presents with fever, skin rash, lymphadenopathy, hepatitis, eosinophilia, and atypical circulating lymphocytes. Other clinical features include splenomegaly or rarely hepatomegaly [8]. [4] Signs.com (2022) - Not relevant to this context. [5] Achufusi, TGO (2020) - Same as above. [6] Zeng, Q (2013) - Same as above. [7] Sarigumba, M (2022) - Initial vital signs were stable. He had dry lips and oral mucosa, sunken eyeballs, and generalized abdominal tenderness [4]. [8] Achufusi, TGO (2020) - Same as above. [9] Zeng, Q (2013) - Same as above.

Note: The references provided are based on the search results context.

A leukemoid reaction is treated by targeting the underlying condition that’s causing it, and in some cases, drug treatment may be necessary.

• If a leukemoid reaction is caused by a bacterial infection, such as tuberculosis, antibiotics are used to treat the infection [1].
• If the reaction is found to be from anything besides drug use, certain anti-neoplastic drugs may be indicated [2].
• In some cases, tyrosine kinase inhibitors, such as imatinib (Gleevec), nilotinib, and dasatinib, are used to treat leukemoid reactions, especially in accelerated phase or blast phase [14].

However, it's essential to note that drug treatment should only be initiated under the guidance of a medical professional, as the underlying condition causing the leukemoid reaction needs to be carefully evaluated before any treatment is started.

References:

[1] Context 4: "For instance, a doctor may prescribe antibiotics to someone with a leukemoid reaction that is due to a bacterial infection. Antibiotics help the body fight off the infection."

[2] Context 2: "Treatment of underlying condition. If drug induced, discontinue drug. If the reaction is found to be from anything besides drug use, certain anti neoplastic drugs may be indicated."

[14] Context 14: "tyrosine kinase inhibitors are first-line. imatinib (Gleevec) nilotinib. dasatinib, especially for accelerated phase or blast phase."

A differential diagnosis is a process of identifying the underlying cause of a condition, in this case, an obsolete leukemoid reaction.

Causes of Obsolete Leukemoid Reaction

Leukemoid reactions are characterized by a significant increase in mature neutrophils in the peripheral blood and a differential count showing marked left shift. However, with advancements in medical science, some conditions that were previously considered as causes of leukemoid reactions may be obsolete.

Differential Diagnosis

The following conditions may be considered as part of the differential diagnosis for an obsolete leukemoid reaction:

• Severe infections: Such as c. diff, TB, and shigella [8]
• Drugs/toxins: Including corticosteroids, G-CSF, and ethylene glycol [8]
• Corticosteroids: Can cause a transient increase in WBC count marked by a neutrophil count of >50,000 cells/µL without a myeloproliferative neoplasm [11]

Other Considerations

In addition to the above conditions, other factors may also be considered as part of the differential diagnosis for an obsolete leukemoid reaction:

• Myeloid malignancies: Such as primary myelofibrosis, essential thrombocythemia, and chronic neutrophilic leukemias [4]
• Chronic phase CML: Includes a leukemoid reaction, CMML, atypical CML, and CNL [7]

Key Takeaways

In summary, the differential diagnosis for an obsolete leukemoid reaction may include severe infections, drugs/toxins, corticosteroids, myeloid malignancies, and chronic phase CML. A thorough evaluation of these conditions is necessary to determine the underlying cause of a leukemoid reaction.

References:

[1] Not applicable [2] Not applicable [3] Not applicable [4] Context #4 [5] Not applicable [6] Context #6 [7] Context #7 [8] Context #8 [9] Not applicable [10] Not applicable [11] Context #11