Differential Diagnosis
- Single most likely diagnosis
- Cystic Fibrosis (CF): This diagnosis is the most likely due to the combination of recurrent chest infections, pale bulky foul-smelling stools (steatorrhea), elevated sweat chloride test, and high stool fat content. These symptoms are classic for CF, which is an autosomal recessive disorder affecting the CFTR gene, leading to abnormal chloride transport and resulting in thick, sticky secretions in various organs, including the lungs and pancreas.
- Other Likely diagnoses
- Shwachman-Diamond Syndrome: This is a rare genetic disorder that affects the pancreas, bone marrow, and skeleton, and can present with similar gastrointestinal and respiratory symptoms, including steatorrhea and recurrent infections. However, it typically also includes neutropenia and skeletal abnormalities.
- Pancreatic Insufficiency: This could explain the steatorrhea and high stool fat, but would not account for the recurrent chest infections or the elevated sweat chloride test.
- Do Not Miss
- Bronchiectasis (not a specific disease but a condition that can result from various causes, including infections, autoimmune diseases, or primary ciliary dyskinesia): It's crucial to consider other causes of recurrent chest infections that could lead to bronchiectasis, as the management and prognosis might differ significantly from CF.
- Primary Ciliary Dyskinesia (Kartagener Syndrome): This condition affects the motility of cilia, leading to recurrent respiratory infections and could be considered, especially if there are situs inversus or other laterality defects.
- Rare diagnoses
- Pearson Syndrome: A rare mitochondrial disorder that affects the pancreas and bone marrow, presenting with steatorrhea, anemia, and neutropenia, but it's much rarer and typically presents in early childhood.
- Congenital Enteropathy: A group of rare disorders affecting the small intestine, leading to severe diarrhea and malabsorption, which could explain some gastrointestinal symptoms but not the full spectrum of the patient's presentation.