Medical Conditions Could Cause Itchy Skin 

In addition to skin conditions, other medical conditions could be associated with itchy skin. The Mayo Clinic lists several internal diseases that might cause itchy skin, including: 

• liver disease;
• celiac disease;
• kidney failure;
• iron deficiency anemia;
• thyroid issues; and
• certain cancers. 

Allergic Reactions Could Cause that Itch 

Other possible causes of itchy skin are allergic reactions to toxins, outdoor stimulants, detergents and cleansers, food, medicine, or makeup. These can trigger an immune system response that causes itchy skin. Learning your triggers is the first step to avoiding flare-ups. Pinpointing the cause can help clear it up and avoid the symptoms.