ZocdocAnswersWhat might have caused my skin rash?

Question

What might have caused my skin rash?

On the side of my arm towards the front I have a series of red marks and splotches that came out of nowhere. They are itchy and won't go away. What is this and how can I treat it?

Answer

If the red marks are spreading over the rest of your body and not just confined to your arm, then they are likely hives, which are an allergic type reaction of the skin to various stimulants. Hives are often provoked by viral infections and can also be caused by typical allergens (like pollen or cat dander). Usually hives are pretty self limiting and tend to go away over a few days. Occasionally hives may be the first sign of a more serious allergic reaction. Therefore, whenever you have hives, you should also look for serious signs like face or lip or tongue swelling or trouble breathing. If you have these symptoms, this requires immediate medical evaluation in an emergency room for a potentially life threatening allergic reaction. If the rash is entirely confined to your arm without any other symptoms, then contact dermatitis might be the cause. Contact dermatitis is a local allergic reaction of the skin to something that comes in contact. Contact dermatitis gets better usually with the application of a topical steroid cream, but more severe cases may require additional medications from your primary care doctor. Please make an appointment with your doctor or dermatologist to discuss this issue in more detail, and to make sure there isn't a more serious issue.

This answer is for general informational purposes only and is not a substitute for professional medical advice.

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