CHRONIC GRANULOMATOUS DISEASE PRESENTING AS COW'S MILK ALLERGY AND EOSINOPHILIC ESOPHAGITIS

Abstract

<h3>Introduction</h3> An infant with failure to thrive was diagnosed with cow's milk allergy (CMA) and eosinophilic esophagitis (EOE). Further work up by multiple specialists considered inborn error of metabolism, cystic fibrosis, infection, or malignancy. He was diagnosed with chronic granulomatous disease (CGD) after 3 weeks in the hospital. <h3>Case</h3> A 2 month-old male with history of formula intolerance was admitted for poor weight gain, vomiting, and bloody stools in the setting of social challenges. The infant was pale-appearing with baseline tachypnea however chest x-ray was unremarkable. Initial immune workup was limited to immunoglobulin levels which were normal. Given his elevated fecal calprotectin, he was diagnosed with CMA. EGD revealed EOE and gastritis. He had persistent leukocytosis to 59,000/mm^3 with 32% eosinophils, anemia, thrombocytosis, and elevated inflammatory markers. This prompted suggestion of bone marrow biopsy to evaluate for leukemia. Prior to this, dihydrorhodamine (DHR) assay confirmed absence of superoxide production in neutrophils. Genetic testing revealed hemizygous pathogenic variant c.469C>T in the CYBB gene associated with X-linked CGD. Mother's DHR was normal suggesting de novo mutation. Chest CT after diagnosis showed right lower lobe inflammatory chronic granulomatous process which was confirmed with lung biopsy. Bacterial and fungal prophylaxis were initiated and curative treatment with hematopoietic is currently being pursued. This patient's genetic variant has been described in a case series to cause very early onset GI manifestations, hypereosinophilia, and hyperleukocytosis with no infections. Persistent failure to thrive and enteropathy with leukocytosis warrants an extensive workup as CGD and other primary immunodeficiencies may present with inflammatory findings.