A diagnosis for itchy skin can come from a doctor, who can perform a blood test, chemistry profile, thyroid function test and chest X-rays, according to Mayo Clinic. These tests determine whether patients with itchy skin have thyroid abnormalities, liver or kidney problems, and any underlying diseases.
Itchy skin has many causes, including Sjögren’s syndrome, allergic contact dermatitis and iron-deficiency anemia, notes Healthgrades. Patients with these conditions have unique symptoms, and doctors diagnose their conditions using various methods.
The defining symptoms of Sjögren’s syndrome are dry eyes and mouth, which is one way doctors diagnose the condition, explains Cleveland Clinic. Patients with Sjögren’s syndrome also experience enlarged parotid glands, fatigue and skin rashes. Doctors diagnose patients with the condition by conducting laboratory tests that look for autoantibodies in the blood or by performing a lip biopsy.
Patients with iron-deficiency anemia have unique symptoms that include weakness, brittle nails, pale skin and shortness of breath, according to MedlinePlus. Doctors order certain blood tests, including a hemoglobin count, to diagnose the condition if the symptoms are indicative of anemia.
In addition to itchy skin, patients with allergic contact dermatitis experience other symptoms, including scaly skin, oozing blisters and hives, reports Cleveland Clinic. Doctors suspect allergic contact dermatitis when a patient has a rash that doesn't go away. If a patch test determines that the patient is allergic to any chemicals, the doctor diagnoses the patient with allergic contact dermatitis.