Overview
A skin rash is a visible change in the skin that can appear as redness, itching, scaling or blisters. It often develops suddenly and affects either isolated spots or larger areas of the body. Many rashes are harmless and clear up on their own, while others point to a cause that needs treatment. How it progresses depends largely on what triggered the rash.
Common causes
Among the most frequent triggers are allergic reactions, for example to foods, medications, skincare products or plants. Infections caused by viruses, bacteria or fungi can also lead to rashes. Chronic skin conditions such as atopic dermatitis or psoriasis play a role as well. Irritation from heat, sweat, friction or stress can further promote the condition. Sometimes the exact cause remains unclear at first despite examination.
When to see a doctor
Have a rash checked by a doctor if it spreads quickly, is very painful, weeps or oozes pus, or does not clear up after a few days. Warning signs such as high fever, a general feeling of illness, or a rash appearing after starting a new medication call for prompt evaluation. Call the emergency number 112 immediately if you experience shortness of breath, swelling of the face or throat, circulatory problems, or a rapidly spreading rash with high fever.