Understanding Post-Injection Inflammation

What causes post-injection inflammation?

The most common cause is the skin or the immune system's response to the needle or the medicine. Less common causes include an allergic reaction to the medicine. In rare cases, an infection at the injection site can occur.

Symptoms of post-injection inflammation

Symptoms at the injection site may include:

• Soreness when touched.

• Swelling.

• Itching.

• Pain.

• Redness.

• Warmth.

• Rash.

Treatment for post-injection inflammation

Treatment depends on what the cause is and how bad the reaction is. Most post-injection inflammation is mild. It goes away on its own in a few hours or days. If treatment is needed, it may include:

• Cold packs. These help reduce swelling, itching, and pain.

• Over-the-counter pain medicines. These help reduce pain and inflammation.

• Prescription medicine. These treat infection.

Possible complications of post-injection inflammation

Be alert for a reaction all over your body. Symptoms include a skin rash, severe itching, or raised red bumps called hives. This kind of reaction can be serious, especially if it affects breathing. If you or your child develops symptoms away from the injection site, call your health care provider right away for more instructions.

When to call your health care provider

Call your health care provider right away if you have:

• A fever of 100.4°F (38°C) or higher, or as directed.

• Severe pain at the injection site.

• Blistering at the injection site.

• Muscle aches.

• An upset stomach (nausea).

• A headache.

• A skin rash, severe itching, vomiting, or hives.

• Symptoms that get worse instead of better.

Call 911

Call 911 if you have:

• Swollen lips, tongue, or throat.

• Trouble breathing.

• A fast heart beat.

• A rash all over your body.

• Weakness or dizziness.