rash_evaluation
Reviewed
A rash evaluation is a procedure to find out what is causing a rash. It includes a medical history, physical exam, and may involve additional tests such as a patch test, skin culture, or skin biopsy. Most rashes are due to contact dermatitis (allergic or irritant), but other causes include skin disorders, infections, insect bites, or heat.
Preparation and collection
You may need to stop taking certain medicines before this test. Tell your provider about everything you take. Do not stop any medicines unless your provider tells you to.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- There is no test for irritant contact dermatitis; diagnosis is based on physical exam, symptoms, and exposure history.
- Results from patch tests, blood tests, and biopsies must be interpreted by your provider in the context of your overall health.
- A rash may be a sign of a serious condition; seek emergency care if symptoms like trouble breathing or rapid spreading occur.
What to do next
To relieve symptoms, your provider may suggest over-the-counter medicines and/or at-home treatments such as cool compresses and baths. Other treatments depend on your specific diagnosis.