An itchy ring finger or an itch near the ring finger can be caused by a skin disorder, such as contact dermatitis, or by a disease that involves the kidneys or liver, such as diabetes, renal failure or obstructive biliary disease, according to Right Diagnosis. Skin disorders are the most common cause when the left ring finger itches.
Contact dermatitis causes a red rash and is caused by contact with an irritating product or substance, according to the Mayo Clinic. Reactions to certain cosmetics and other skin care products are common causes of contact dermatitis. It can also result from switching to new laundry detergent or other products.
Scabies and atopic dermatitis are two other skin conditions that can cause the left ring finger to itch. Patients should visit a family doctor or dermatologist to determine the precise nature of the disorder or disease because specific skin conditions require different types of treatment.
Renal failure, diabetes and other conditions of the kidneys and liver can cause itchiness of the ring finger and other parts of the body. Diabetics have an increased risk of skin complications, according to the American Diabetes Association. Fungal and bacterial infections are two possibilities, but a physician should evaluate the problem in order to start effective treatment.