Differential Diagnosis for Onset of Extra Fatigue and Muscle and Joint Aches Two Weeks After Starting Oral Iron Supplementation

• Single Most Likely Diagnosis
  • Iron-induced gastrointestinal side effects or iron overload: This is the most likely diagnosis because oral iron supplementation is known to cause gastrointestinal side effects such as nausea, vomiting, diarrhea, and constipation, which can lead to fatigue and muscle aches due to dehydration and electrolyte imbalances. Additionally, iron overload can cause symptoms like fatigue, joint pain, and muscle weakness.
• Other Likely Diagnoses
  • Anaphylactoid reaction to iron: Some individuals may experience an allergic reaction to oral iron, which can manifest as fatigue, muscle and joint aches, and other systemic symptoms.
  • Gastrointestinal infection or inflammation: Oral iron can alter the gut microbiome, potentially leading to gastrointestinal infections or inflammation, which can cause fatigue, muscle aches, and joint pain.
  • Vitamin deficiency (e.g., vitamin B12 or folate deficiency): Iron supplementation can sometimes mask underlying vitamin deficiencies, which can cause fatigue, muscle weakness, and joint pain.
• Do Not Miss Diagnoses
  • Hemochromatosis: A genetic disorder that causes the body to absorb too much iron, leading to iron overload and potentially life-threatening complications if left untreated.
  • Iron-induced oxidative stress and damage: Excessive iron intake can lead to the formation of free radicals, causing oxidative stress and damage to tissues, which can manifest as fatigue, muscle aches, and joint pain.
• Rare Diagnoses
  • Porphyria cutanea tarda: A rare genetic disorder that can cause iron overload and lead to symptoms like fatigue, muscle weakness, and joint pain.
  • Iron-refractory iron deficiency anemia (IRIDA): A rare genetic disorder that causes iron deficiency anemia despite adequate iron intake, which can lead to fatigue, muscle aches, and joint pain.