What does an eosinophil count of 0.86 and a basophil count of 0.10 indicate in a CBC result?

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Interpretation of CBC Results: Eosinophil 0.86 and Basophil 0.10

Normal Range Assessment

Your eosinophil count of 0.86 × 10⁹/L is elevated above the upper limit of normal (0.45 × 10⁹/L), while your basophil count of 0.10 × 10⁹/L falls within the normal range. 1

Clinical Significance of Your Results

Eosinophil Elevation (0.86 × 10⁹/L)

  • Your eosinophil level represents mild eosinophilia, falling between the normal upper limit (0.45 × 10⁹/L) and the threshold for hypereosinophilia (1.5 × 10⁹/L). 1

  • At this level (0.75-1.0 × 10⁹/L range), there is a more than twofold increased risk of hematological malignancies, though this risk plateaus around 1.0 × 10⁹/L. 2

  • Eosinophil counts in this range are commonly associated with parasitic infections (particularly in travelers from tropical regions), allergic conditions, drug reactions, or eosinophilic tissue disorders. 3, 1

Basophil Level (0.10 × 10⁹/L)

  • Your basophil count is normal and requires no specific evaluation. Normal basophil levels effectively exclude basophilic crisis or mixed-lineage hematological disorders. 4

Recommended Diagnostic Workup

Initial Clinical Assessment

  • Evaluate for travel history to tropical/subtropical regions within the past several years, as helminth infections are the most common cause of mild eosinophilia in this context. 3, 1

  • Assess for allergic conditions including asthma, allergic rhinitis, atopic dermatitis, and food allergies, which are present in 50-80% of patients with eosinophilic disorders. 3

  • Review all current medications and supplements to identify potential drug-induced eosinophilia. 3

  • Inquire about gastrointestinal symptoms (dysphagia, food impaction, abdominal pain) that may suggest eosinophilic esophagitis, which occurs with peripheral eosinophilia in 10-50% of adults. 3, 1

Laboratory and Diagnostic Testing

  • Obtain stool microscopy for ova and parasites (three separate samples) and consider serology for specific helminth infections based on travel exposure. 3

  • Repeat eosinophil count in 1 month to determine if elevation is persistent, as hypereosinophilia is formally defined as >1.5 × 10⁹/L on two examinations at least one month apart. 1

  • If gastrointestinal symptoms are present, perform upper endoscopy with six biopsies from at least two different esophageal sites to evaluate for eosinophilic esophagitis (diagnostic threshold: >15 eosinophils per 0.3 mm²). 5, 3

Treatment Considerations

For Parasitic Infections (if identified)

  • Albendazole 400 mg single dose for most helminth infections. 3

  • Ivermectin 200 μg/kg single dose for strongyloidiasis. 3

  • For asymptomatic returning travelers with eosinophilia, empiric treatment with both albendazole 400 mg plus ivermectin 200 μg/kg may be considered. 3

For Allergic Conditions

  • Optimize treatment of underlying atopic diseases (asthma, allergic rhinitis, atopic dermatitis) as these can contribute to peripheral eosinophilia. 3

Important Clinical Caveats

  • Eosinophil counts show substantial variability with seasonal differences of approximately 20% between summer and winter months, and single measurements may not be sufficient for diagnosis. 6

  • Nasal polyps increase eosinophil levels by 38%, while current smoking decreases levels by 23%. 6

  • Blood eosinophil levels do not always correlate with tissue eosinophilia in conditions like eosinophilic esophagitis, so tissue diagnosis may be necessary despite modest peripheral eosinophilia. 3

  • Eosinophil counts between 0.5-1.0 × 10⁹/L warrant investigation even though they fall below the formal definition of hypereosinophilia, as risks of underlying pathology are still elevated. 2

References

Guideline

Upper Limit of Normal for Blood Eosinophils in Blood Count

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Management of Consistently Elevated Eosinophil Count

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Mixed-lineage eosinophil/basophil crisis in MDS: a rare form of progression.

European journal of clinical investigation, 2008

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

A Comprehensive Analysis of the Stability of Blood Eosinophil Levels.

Annals of the American Thoracic Society, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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