Differential Diagnosis for 1 Year of Dizziness, Fatigue, Chills, Right Sided Numbness, and Confusion

Given the patient's symptoms and the presence of mold in the house, along with negative labs and unremarkable neurology and cardiology referrals, the following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Chronic Mold Exposure: The presence of mold in the house is a significant clue. Chronic exposure to mold can cause a variety of symptoms including fatigue, dizziness, chills, and neurological symptoms like numbness and confusion due to mycotoxin exposure.

• Other Likely Diagnoses

  • Multiple Sclerosis: Although neurology referral was unremarkable, MS can have a highly variable presentation and sometimes initial evaluations can be normal. The right-sided numbness could suggest a demyelinating lesion.
  • Lyme Disease or Other Tick-Borne Illnesses: These can cause a wide range of symptoms including neurological manifestations, fatigue, and sometimes confusion, especially if the central nervous system is involved.
  • Vitamin Deficiencies (e.g., B12): Can cause neurological symptoms, fatigue, and sometimes confusion. Although labs are mentioned as negative, specific vitamin levels might not have been checked.
  • Hypothyroidism: Can cause fatigue, dizziness, and sometimes neurological symptoms. Although labs are negative, thyroid function tests might need to be repeated or evaluated in the context of symptoms.

• Do Not Miss Diagnoses

  • Brain Tumor: The pending head CT will be crucial. A brain tumor could explain the focal neurological symptoms (right-sided numbness) and confusion.
  • Central Nervous System Vasculitis: This is a serious condition that could explain the neurological symptoms and would require prompt diagnosis and treatment.
  • Infectious Diseases (e.g., Neurosyphilis, HIV): These can cause a wide range of neurological symptoms and would be critical to diagnose due to their treatability and potential for severe outcomes if missed.
  • Carbon Monoxide Poisoning: Chronic exposure to low levels of carbon monoxide can cause fatigue, dizziness, confusion, and other neurological symptoms, and is often associated with indoor environments.

• Rare Diagnoses

  • Mitochondrial Disorders: These are a group of disorders caused by dysfunctional mitochondria, affecting multiple systems and could potentially explain the wide range of symptoms.
  • Heavy Metal Poisoning: Exposure to certain heavy metals (like lead or mercury) can cause neurological symptoms, fatigue, and confusion.
  • Porphyrias: A group of rare disorders that can cause neurological symptoms, fatigue, and sometimes confusion, although they are less likely given the broad range of symptoms and the presence of mold.

Each of these diagnoses should be considered in the context of the patient's overall clinical picture, and further testing or referral may be necessary to rule out certain conditions. The presence of mold and the broad range of symptoms suggest an environmental or toxic cause, but it's crucial to also consider other systemic and neurological conditions.