Differential Diagnosis for Extremities Cold but Low Grade Fever

• Single most likely diagnosis
  • Hypothyroidism: This condition can cause feelings of coldness in the extremities due to decreased metabolism, and a low-grade fever can sometimes be present, possibly due to an underlying infection or inflammation that the body is not effectively fighting off due to the metabolic slowdown.
• Other Likely diagnoses
  • Anemia: Can lead to feelings of coldness, especially in the hands and feet, due to reduced oxygen delivery to tissues. A low-grade fever might be present if there's an underlying chronic disease or infection.
  • Poor Circulation (Peripheral Artery Disease): Reduced blood flow to the extremities can cause them to feel cold. A low-grade fever could be related to an underlying condition affecting circulation or an infection.
  • Infection (e.g., sinusitis, urinary tract infection): Some infections can cause a low-grade fever and, depending on their impact on the body, might also lead to feelings of coldness in the extremities due to systemic effects.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Sepsis: Although it often presents with high fever, in the early stages or in elderly patients, sepsis can manifest with hypothermia and a low-grade fever. It's critical to consider this diagnosis due to its high mortality rate if not promptly treated.
  • Disseminated Intravascular Coagulation (DIC): This condition can lead to both thrombotic and hemorrhagic complications, including cold extremities due to poor circulation. Fever can be present due to the underlying cause of DIC.
  • Endocarditis: Infective endocarditis can cause fever and, through embolic phenomena, affect circulation to the extremities, making them feel cold.
• Rare diagnoses
  • Raynaud’s Phenomenon: A condition that affects blood flow to the fingers and toes, and sometimes the ears, nose, and lips, causing them to turn blue or feel cold in response to cold temperatures or stress. While not typically associated with fever, it could be considered in the differential if other symptoms are present.
  • Mitral Valve Prolapse with associated autonomic dysfunction: Some patients with mitral valve prolapse can experience autonomic nervous system dysfunction, leading to vasomotor instability and feelings of cold extremities. A low-grade fever could be unrelated or due to an associated condition.