Management of Consistently Elevated Eosinophil Count

Diagnostic Approach

The management of consistently elevated eosinophil counts requires a systematic evaluation for underlying causes, with referral to appropriate specialists based on clinical presentation and severity of eosinophilia, as recommended by the Journal of Infection 1
Assess for common causes of mild eosinophilia, including parasitic infections, especially in those with travel history, according to the Journal of Infection 2, 1
For patients with gastrointestinal symptoms, consider endoscopy with multiple biopsies to evaluate for eosinophilic esophagitis, which is supported by Gastroenterology 3
Stool microscopy for parasitic infections and serology for specific helminth infections based on travel history are recommended by the Journal of Infection 2, 1

For parasitic infections, albendazole 400 mg as a single dose for most helminth infections is recommended by the Journal of Infection 2
For strongyloidiasis, ivermectin 200 μg/kg as a single dose is suggested by the Journal of Infection 1
For returning travelers with asymptomatic eosinophilia, empiric treatment with albendazole 400 mg single dose plus ivermectin 200 μg/kg single dose may be considered, as per the Journal of Infection 1
Topical steroids have been shown to decrease blood eosinophil counts in 88% of patients with eosinophilic esophagitis, according to Gastroenterology 3

Follow-up eosinophil counts should be obtained after treatment to assess response, as recommended by Gastroenterology 3
For eosinophilic esophagitis, histological remission is defined as <15 eosinophils per 0.3 mm² in tissue biopsies, according to Gut 4

The American Gastroenterological Association suggests that eosinophilic esophagitis (EoE) diagnosis requires tissue biopsy showing >15 eosinophils per 0.3 mm² in esophageal tissue samples 5, 6
In treated EoE, histological remission is defined as <15 eosinophils per 0.3 mm² in tissue, with deep remission being <5 eosinophils per 0.3 mm² 7, 8
Peripheral eosinophilia occurs in 10-50% of adults and 20-100% of children with eosinophilic esophagitis, though usually only modestly elevated (2-fold) 9

The American Gastroenterological Association recommends assessing for allergic conditions including allergic rhinitis, atopic dermatitis, and asthma 9
Evaluation for aeroallergen sensitivity is recommended, given high rates (50-80%) of allergic diatheses in patients with eosinophilic conditions 9
If gastrointestinal symptoms are present (dysphagia, food impaction), consider endoscopy with multiple biopsies (six biopsies from at least two different sites) to evaluate for eosinophilic esophagitis 6, 10

The American Society for Gastrointestinal Endoscopy suggests that peripheral eosinophil counts may not always correlate with tissue eosinophilia in conditions like eosinophilic esophagitis 7, 11

Support from an experienced dietitian is recommended for patients on elimination diets, such as a two-food elimination diet, for 8-12 weeks 12

Combination therapy of drugs and diet should be reserved for selected patients who fail monotherapy 12
Allergy testing to foods is not recommended for choosing dietary restriction therapy for eosinophilic esophagitis 12

Patients with eosinophilia and concomitant atopic disease should have optimization of treatment for their allergic conditions 13
For patients with refractory eosinophilia and/or significant concomitant atopic disease, consider joint management by a gastroenterologist and specialist allergy clinic 13

If symptoms recur while on treatment, repeat endoscopy for assessment and to obtain further histology 13