The development of a nodule at the injection site is a known but rare adverse event following immunisation (AEFI). Nodules are defined as the presence of a palpable, firm, discrete or well-demarcated soft tissue lump at the site of immunisation in the absence of heat, erythema (redness) or signs of abscess.
While swelling and minor bruising can happen after a shot, they usually get better within a day or so. However, if swelling and discoloration persist, it may signify an infection. 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.
Injection site reactions are areas of skin redness, swelling, and warmth. They can develop after you get a vaccine or an injectable medication. Injection site reactions will go away on their own. In the meantime, you can get relief with warm compresses and over-the-counter pain medications.
These include pain, itching, swelling or redness around the site of injection. These reactions are usually mild and last for 1–2 days. Rarely, injection site reactions can be quite large and may extend from joint to joint (e.g. shoulder to elbow) or may cross a joint.
Injecting too much liquid can cause problems like scarring and abscesses (a pus-filled lump under your skin).
A nodule can persist for weeks and sometimes months. They are usually asymptomatic but can be tender and/or itchy. They are often reported by parents to feel like a 'pea' size lump under the skin. They usually resolve spontaneously without treatment or investigation.
Painless lump at the injection site 1 or 2 weeks later. The lump is harmless and will disappear in about 2 months. Call your provider within 24 hours if it turns red or is tender.
To help prevent infection when giving yourself a shot, always wash your hands, clean the injection site, and keep your needles sterile. If you notice signs of infection, call your doctor. These signs include: Increased pain, swelling, warmth, or redness around the injection site.
Published on Mar 06, 2017 and last reviewed on Aug 16, 2022 - 1 min read. An Injection Abscess is a pus filled mass that occurs at the site where injection was administered.
Injecting a small air bubble into the skin or a muscle is usually harmless. But it might mean you aren't getting the full dose of medicine, because the air takes up space in the syringe.
If you use your arm normally after vaccination, it will help ease the soreness more quickly. In some people, vaccines may cause a lump or hardness at the injection site which persists for a few weeks. If your arm is red, hot and/or sore, place an ice pack over the affected area. You can take paracetamol.
See a GP if:
your lump lasts more than 2 weeks. a lump grows back after it's been removed. you have a lump in the breast or testicles. you have a swelling on the side of your neck, armpit or groin that does not go down.
Well the reason a swollen arm may happen is because the vaccine is a foreign substance in the body and this is what causes an allergic reaction. Lots of cells will release histamine and other chemicals which go into the bloodstream and will cause a reaction.
Abscesses begin with redness, swelling, and tenderness at an injection site and develop into an infection with a hard, pus-filled core.
Symptoms of Vaccine Reactions
Shot sites can have swelling, redness and pain. Most often, these symptoms start within 24 hours of the shot. They most often last 3 to 5 days. With the DTaP vaccine, they can last up to 7 days.
Localized complications include injection site abscesses, suppurative regional lymphadenitis, and pain, redness, or swelling lasting longer than 3 days. These reactions may occur from 0.1% to 19% of vaccinations and tend to occur more frequently in adults than in infants less than 6 months old [172].
Skin abscesses usually are red, swollen, and warm to the touch, and might leak fluid. An abscess that forms in the surface of the skin might look like an unhealed wound or a pimple. An abscess that forms underneath the skin may create a swollen bump. The area can be painful and tender.
Injection abscess following IM injection has been reported by various authors. Most cases are due to Staphylococcus aureus either as methicillin sensitive S. aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA) (2).
Lipohypertrophy is a lump of thickened tissue that can develop in the subcutaneous fat layer. It is common in people who regularly receive injections for certain health conditions, such as diabetes. The lumps are not tumors, and they are not malignant, but they may cause delays in the absorption of medication.
Medical Treatment
The area will be covered with an antiseptic solution and sterile towels placed around it. The doctor will cut open the abscess and totally drain it of pus and debris. Once the sore has drained, the doctor may insert some packing into the remaining cavity to allow the infection to continue to drain.
Injections given in the hand and sole of the foot tend to hurt the most.
Diagnosis is based on the four cardinal signs of infection: erythema, pain, swelling and warmth, usually accompanied by systemic signs of fever and toxicity. It is important to note that vaccination rarely introduces bacteria into the tissues in the modern setting of single-dose vials and single-use injection supplies.
Since Fragmin is injected into the skin, the injection site may be sore or red. You may even get a bruise ranging from the site of a pinprick to the size of a quarter. If you find a lump at the injection site, don't worry. It is just fluid and will be absorbed into your body.