Hives diagnosis

When to see a provider for hives

Mild cases of hives or angioedema can be treated at home. You should see your provider if your symptoms persist for more than a few days. Seek immediate medical attention if you’re developing hives and have trouble breathing. If this happens, you may be having an anaphylactic reaction as a result of exposure to an allergen.

Hives vs. rash

Hives are a particular type of rash.^[20] There are many other types of rashes. Some common rashes and their causes^[21] include:

• Eczema (atopic dermatitis): A condition in which the skin develops cracked, scaly, itchy, patches. People with allergies or asthma sometimes get eczema.
• Psoriasis: An autoimmune condition that causes scaly, itchy, dry patches, especially along the scalp and over joints or fingernails.
• Impetigo^[22]: A highly contagious bacterial infection most common in children. It causes red sores on the face that burst and form honey-colored crusts.
• Shingles: A reactivation of the chickenpox virus that causes a painful rash. Other childhood illnesses, such as measles, roseola, rubella, hand-foot-and-mouth disease, fifth disease, and scarlet fever, can all cause rashes.

Medications, including antibiotics, NSAIDs, and anti-seizure medications, may cause rashes. Insect and arachnid bites or stings from fleas, ticks, poisonous spiders, and other bugs may also trigger allergic reactions that can cause rashes. It can be difficult to distinguish between these different types of skin rashes. If you have a rash, see your healthcare provider. They can help you determine the source of the rash using a skin test and determine the right course of treatment.

What do hives look like?

Hives are raised, pink, itchy bumps that can vary in size from a few millimeters to several centimeters. The center of a hive will turn white when pressed. This is called blanching.^[23] If you have a rash, a healthcare provider will examine^[24] the abnormal areas in your skin and take a medical history to identify the possible causes of your symptoms. Sometimes, your provider will use a test, such as a skin-prick allergy test, to help diagnose your rash. You should see your provider if you suspect that you may have hives or another type of skin condition.