KEY CLINICAL MESSAGE: Early recognition and management of seronegative celiac disease, even in the absence of typical serological markers, can prevent complications and ensure better health outcomes in pediatric patients. Consideration of a gluten-free diet in similar cases can lead to significant clinical improvement. ABSTRACT: Celiac disease, characterized by its diverse clinical manifestations, often necessitates adherence to a gluten-free diet, particularly in pediatric patients for optimal growth and development. This report presents the case of an 11-year-old male who exhibited recurrent symptoms of fever and diarrhea progressing to edema and pallor, with a history dating back to age 3. Laboratory findings revealed pancytopenia, hypoalbuminemia, and proteinuria. Despite negative serological markers, noninvasive tests, along with clinical improvement on a gluten-free diet and supportive measures within a month, suggested celiac disease complicated by transient protein-losing enteropathy and vitamin B12 deficiency. It is important to note that other malabsorption disorders can also show clinical improvement following a gluten-free diet. Additionally, the antibiotic treatment received by the patient could have addressed other possible causes of malabsorption, complicating the differential diagnosis. This case highlights the importance of early recognition and management of celiac disease, especially in pediatric patients, to prevent complications and promote optimal health outcomes.