Differential Diagnosis for Itching
- Single most likely diagnosis
- Dry skin (xerosis): This is a common condition that can cause itching due to the lack of moisture in the skin, especially during dry weather or in older adults.
- Other Likely diagnoses
- Eczema (atopic dermatitis): A chronic skin condition characterized by itchy, inflamed skin, often associated with allergies or asthma.
- Allergic reactions: Itching can be a symptom of an allergic reaction to substances like insect bites, certain foods, or medications.
- Psoriasis: An autoimmune condition that speeds up the life cycle of skin cells, causing cells to build up rapidly on the surface of the skin, leading to itching and inflammation.
- Scabies: A contagious skin infestation by the mite Sarcoptes scabiei, causing intense itching, especially at night.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Malignancy (e.g., lymphoma, leukemia): Itching can be a symptom of certain types of cancer, although this is relatively rare.
- Liver disease (e.g., primary biliary cirrhosis): Itching can be a symptom of liver disease due to the buildup of bile salts in the skin.
- Kidney disease: Itching can occur in patients with chronic kidney disease, especially those on dialysis.
- Thyroid disorders: Both hyperthyroidism and hypothyroidism can cause itching, although this is less common.
- Rare diagnoses
- Neurological disorders (e.g., multiple sclerosis, neuropathy): Itching can be a symptom of certain neurological conditions, although this is relatively rare.
- Insect infestations (e.g., bed bugs, fleas): Itching can be caused by bites from certain insects.
- Aquagenic pruritus: A rare condition characterized by itching after exposure to water.
- Cholestasis of pregnancy: A condition that occurs in some pregnant women, causing itching due to the buildup of bile salts in the skin.