Differential Diagnosis for Itching without Rash with Myalgia

Single Most Likely Diagnosis

• Dry Skin (Xerosis): This is a common condition that can cause itching without a rash, often accompanied by myalgia due to the discomfort and scratching that can lead to muscle pain.

Other Likely Diagnoses

• Uremic Pruritus: Associated with chronic kidney disease, this condition can cause itching without a rash, along with myalgia due to the buildup of toxins.
• Hepatic Pruritus: Certain liver diseases, like primary biliary cirrhosis, can cause itching without a visible rash, sometimes accompanied by muscle pain.
• Iron Deficiency: Itching can be a symptom of iron deficiency anemia, and myalgia can occur due to the lack of iron affecting muscle function.
• Thyroid Disorders: Both hypothyroidism and hyperthyroidism can cause itching and muscle pain without a rash.

Do Not Miss Diagnoses

• Multiple Myeloma: A type of blood cancer that can cause itching without a rash, along with bone pain that might be mistaken for myalgia. Early detection is crucial.
• Lymphoma: Certain types of lymphoma can cause itching without a rash, and myalgia can be present due to the disease's impact on the body.
• Polycythemia Vera: A rare blood disorder that can cause itching, especially after warm baths, and myalgia due to increased blood viscosity.

Rare Diagnoses

• Eosinophilic Fasciitis: A rare condition characterized by inflammation of the fascia, leading to itching, myalgia, and sometimes skin thickening without a typical rash.
• Sjögren's Syndrome: An autoimmune disorder that can cause itching and myalgia among its many symptoms, often without a rash.
• Cholestasis of Pregnancy: A condition occurring in pregnancy where bile flow is reduced, leading to itching without a rash and potential muscle pain.