Differential Diagnosis for a 15-year-old Female with Abnormal Iron Studies

The patient presents with iron deficiency anemia, as indicated by low iron levels (19 μg/dL), low iron saturation (4%), and low ferritin (4 ng/mL), along with a hemoglobin (Hb) level of 9.9 g/dL and mean corpuscular hemoglobin concentration (MCHC) of 30.5 g/dL.

• Single Most Likely Diagnosis:

  • Iron Deficiency Anemia (IDA) - This is the most likely diagnosis given the patient's low iron levels, low iron saturation, and low ferritin levels, which are all indicative of iron deficiency. The low Hb and MCHC further support this diagnosis.

• Other Likely Diagnoses:

  • Anemia of Chronic Disease - Although less likely than IDA given the very low ferritin, anemia of chronic disease could present with low iron and saturation, but typically ferritin would be elevated as an acute phase reactant.
  • Thalassemia Trait - The low MCHC could suggest a thalassemia trait, but the iron studies do not typically support this diagnosis unless there's coexisting iron deficiency.
  • Chronic Blood Loss - This could lead to iron deficiency anemia, especially if the loss is occult (e.g., menstrual, gastrointestinal).

• Do Not Miss Diagnoses:

  • Celiac Disease - This condition can lead to iron deficiency anemia due to malabsorption and would be critical not to miss due to its potential for long-term complications if left untreated.
  • Inflammatory Bowel Disease (IBD) - Similar to celiac disease, IBD can cause iron deficiency through malabsorption, chronic blood loss, and inflammation.
  • Malignancy - Though rare in this age group, malignancies can cause anemia of chronic disease or iron deficiency anemia through various mechanisms.

• Rare Diagnoses:

  • Sideroblastic Anemia - A group of disorders characterized by the presence of ringed sideroblasts in the bone marrow, which could present with variable iron studies but often with elevated ferritin.
  • Pyridoxine-responsive Anemia - A rare condition that could present with anemia and might have abnormal iron studies, though it's more commonly associated with sideroblastic anemia.
  • Genetic Disorders of Iron Metabolism - Such as hereditary hemochromatosis or juvenile hemochromatosis, though these would typically present with elevated iron stores rather than deficiency.