What is the interpretation of my complete blood count (CBC) results showing elevated eosinophils?

Interpretation of CBC Results with Elevated Eosinophils

Your CBC results show mild eosinophilia (0.8 x 10^9/L) with all other parameters within normal range, which most likely indicates an allergic condition requiring further evaluation of allergic, respiratory, or gastrointestinal symptoms.

Understanding Eosinophilia

Eosinophilia is defined as an elevated absolute eosinophil count (AEC) in peripheral blood:

• Mild: >0.5 x 10^9/L
• Moderate: >1.5 x 10^9/L (hypereosinophilia)
• Severe: >5.0 x 10^9/L

Your eosinophil count of 0.8 x 10^9/L is above the normal range (0.0-0.5 x 10^9/L), indicating mild eosinophilia 1.

Clinical Significance and Causes

The most common causes of mild eosinophilia include:

1. Allergic conditions:

   • Allergic rhinitis
   • Asthma
   • Atopic dermatitis
   • Food allergies

2. Medication reactions:

   • Antibiotics
   • NSAIDs
   • Antiepileptics

3. Parasitic infections:

   • Helminthic infections
   • Certain protozoan infections 2, 3

4. Other conditions:

   • Eosinophilic gastrointestinal disorders
   • Chronic rhinosinusitis with nasal polyps
   • Autoimmune disorders 1

Recommended Evaluation

Since your eosinophilia is mild and all other blood parameters are normal, the following approach is recommended:

1. Focused history:

   • Allergic symptoms (sneezing, itching, rashes)
   • Respiratory symptoms (cough, wheezing, shortness of breath)
   • Gastrointestinal complaints (dysphagia, heartburn, abdominal pain)
   • Recent travel history
   • New medications
   • Family history of allergic disorders 1, 3

2. Initial laboratory tests to consider:

   • Serum IgE levels
   • Allergen-specific IgE testing if allergic symptoms are present
   • Stool examination for ova and parasites if GI symptoms or travel history 1

When to Consider Further Evaluation

Further evaluation should be considered if:

• Eosinophilia persists for >3 months
• Eosinophil count increases to ≥1.5 x 10^9/L
• You develop symptoms suggesting organ involvement (cardiac, pulmonary, neurological)
• You have treatment-resistant sinus disease or nasal polyps 4, 1

Treatment Considerations

Treatment depends on the underlying cause:

• For allergic disorders: antihistamines, corticosteroids, and allergen avoidance
• For parasitic infections: appropriate antiparasitic therapy
• For medication reactions: discontinuation of the offending drug 1

Follow-up Recommendations

• Repeat CBC in 4-6 weeks to monitor eosinophil count
• If eosinophilia persists at ≥1.5 x 10^9/L for more than 3 months, referral to a hematologist is recommended 1

Important Caveats

• Mild eosinophilia (as in your case) is typically associated with allergic conditions and rarely indicates serious underlying disease 3
• Normal blood eosinophil counts do not exclude tissue eosinophilia 1
• Eosinophil counts can fluctuate due to diurnal variation and stress 3