We are currently looking for oncology pharmacists to join our team! If you are interested in joining ChemoExperts, please click here. Not interested? Hide this message.

Side Effect: Injection Site Redness

What is Injection Site Redness?

Injection site redness, also known as erythema, is a common side effect of intravenous (IV) or subcutaneous (SC) medication administration. It occurs due to inflammation and irritation at the site of injection. Injection site redness can vary in severity and appearance, ranging from mild pinkish coloration to a dark red or purplish hue. In some cases, the redness may be accompanied by swelling, warmth, and pain.

What does Injection Site Redness look like?

Symptoms will occur at the injection site and may include redness, swelling, itching, pain, and warmth. The reaction may happen right away or it may start hours after the injection. In most cases, the reaction isn't serious and goes away on its own.

Injection Site Redness

Click to enlarge

Who gets Injection Site Redness?

Injection site redness can happen to anyone receiving an injectable medication but is most common when a medication is given subcutaneously. The appearance and severity of injection site redness can vary depending on the medication, dose, and patient. The most common cause for injection site redness is the skin or the immune system's response to the needle or the medicine.

How long does last?

The duration of injection site redness or inflammation varies, but in most cases, it will resolve in 1-2 days. More severe reactions may take longer to recover from.

How to prevent Injection Site Redness

The risk of infusion site redness can be lowered by taking a histamine blocker such as diphenhydramine (Benadryl®), cetirizine (Zyrtec®), or loratadine (Claritin®) 1-3 hours before the injection.

How to treat Injection Site Redness

Injection site redness can be treated by applying a cold compress to the site or by taking a histamine blocker to help with redness, itching, and swelling. If the site is painful then an over-the-counter pain reliever such as acetaminophen (Tylenol®) or a nonsteroidal anti-inflammatory drug (NSAID) may be used. NSAIDs such as ibuprofen (Advil®, Motrin®) can also help reduce inflammation, swelling and itching but patients should receive permission from their doctor to make sure these medications are safe with their current treatment.


1) Roy SR, Sigmon JR, Olivier J, et al. Increased frequency of large local reactions among systemic reactors during subcutaneous allergen immunotherapy. Ann Allergy Asthma Immunol 2007;99(1):82-6

2) Cox L, Larenas-Linnemann D, Lockey RF, et al. Speaking the same language: The World Allergy Organization Subcutaneous Immunotherapy Systemic Reaction Grading System. J Allergy Clin Immunol 2010;125(3):569-74

3) Calabria CW, Coop CA, and Tankersley MS. The LOCAL Study: Local reactions do not predict local reactions in allergen immunotherapy. J Allergy Clin Immunol 2009;124(4):739-44

Created: January 2, 2024 Updated: January 30, 2024