Dyshidrosis – Diagnosis and treatment – Mayo Clinic

In most cases, your doctor can diagnose dyshidrosis based on a physical exam. No lab test can specifically confirm a diagnosis of dyshidrosis, but your doctor may suggest tests to rule out other skin problems that have similar symptoms. For example, a scraping of your skin can be tested for the type of fungus that causes athlete’s foot.

https://www.mayoclinic.org/diseases-conditions/dyshidrosis/diagnosis-treatment/drc-20352348