However, as with all medications, there can be serious adverse reactions or side effects that require prompt medical care.
This article explains some serious injection reactions that you should be aware of and what to do if you experience them.
What Is an Injection Site Reaction?
An injection site reaction is your body’s response to an immunization or other injection at the site where it was administered. It typically manifests as swelling, pain, rash, redness, or bleeding.
Injection site reactions are usually caused by an immune response to the needle, vaccine, or other medicine. These types of reactions are typically mild and resolve in a day or two without treatment.
Less commonly, injection reactions are due to an infection or allergy. Some may be easily treated, while others may be far more serious and lead to a potentially deadly, all-body reaction (such as anaphylaxis or sepsis).
Certain reactions to an injection are potentially serious and should be evaluated by a healthcare provider. If you have any of the following symptoms after an injection, seek medical attention right away.
By and large, allergies tend to happen quickly, while symptoms of an infection may take one to 10 days to appear.
While many infections occur due to a self-administered injection, such as with diabetes or autoimmune disorders. However, they can also happen at the healthcare provider’s office or hospital if the person administering the injection does not adhere to aseptic techniques.
While it is not uncommon to have localized swelling or redness for a day or two following an injection (or even longer for certain types of intramuscular shots), some symptoms warrant further investigation. These include:
Injection site that is tender to the touchFeverBody achesCreeping discoloration
In some cases, the pain may be extreme but not particularly dangerous (such as when an intramuscular injection accidentally hits the sciatic nerve). But, at other times, it may be due to an infection that might only get worse if it’s not untreated.
A lump under the skin that feels soft, mushy, and painful may indicate a developing abscess. An abscess is a walled-off collection of pus. It is often warm to the touch and accompanied by enlarged lymph nodes, small bean-shaped glands that are part of the immune system.
You should never squeeze abscesses. That’s because to prevent infection from spreading throughout the body, a healthcare provider must properly drain it. If you try yourself, it could burst under the skin and spread the infection through the bloodstream, causing a potentially life-threatening blood infection known as sepsis.
Signs a lump may be an abscess include:
The lump oozes: While a bit of drainage following an injection may be expected (caused by medication leaking out of the needle track), a doctor should look at any discolored or abnormal discharge immediately. The swelling grows: If the lump is small and you’re not sure if it’s an abscess, take a pen and draw a circle along the border. If it starts to expand beyond the edge or fails to go away in several hours, call a healthcare provider to look at it as soon as possible.
The first signs of anaphylaxis may be similar to those for an allergy, including a runny nose and congestion (rhinitis), and an itchy skin rash. However, within 30 minutes or so, more severe symptoms can develop, including:
Coughing, wheezing, and shortness of breath Chest tightness Hives Dizziness or fainting Rapid or irregular heartbeat Weak pulse Facial swelling Swollen or itchy lips or tongue Difficulty swallowing A blueish tinge to the lips, fingers, or toes (cyanosis) Pale, clammy skin Nausea, vomiting, or diarrhea
People who have anaphylaxis often report having a feeling of impending doom and panic. Anaphylaxis can lead to shock, coma, or even death if left untreated.
