Lipohypertrophy is an abnormal accumulation of fat underneath the surface of the skin. It’s most commonly seen in people who receive multiple daily injections, such as people with type 1 diabetes. In fact, up to 50 percent of people with type 1 diabetes experience it at some point.
Repeated insulin injections in the same location can cause fat and scar tissue to accumulate.
The main symptom of lipohypertrophy is the development of raised areas under the skin. These areas may have the following characteristics:
- small and hard or large and rubbery patches
- surface area over 1 inch in diameter
- a firmer feel than elsewhere on the body
Areas of lipohypertrophy can cause delays in absorption of medication administered to the affected area, like insulin, which can result in difficulties controlling blood sugar.
Lipohypertrophy areas should not:
- be hot or warm to the touch
- have redness or unusual bruising
- be noticeably painful
These are all symptoms of a potential infection or injury. See a doctor as soon as possible if you have any of these symptoms.
Lipohypertrophy is not the same as when an injection hits a vein, which is a temporary and one-time situation and has symptoms that include bleeding and a raised area that may be bruised for a few days.
It’s common for lipohypertrophy to go away on its own if you avoid injecting in the area. In time, the bumps may get smaller. Avoiding the injection site is one of the most important parts of treatment for most people. It can take anywhere from weeks to months (and sometimes up to a year) before you may see any improvement.
In severe cases, liposuction, a procedure that removes fat from under the skin, may be used to reduce the bumps. Liposuction gives immediate results and can be used when avoiding the injection site hasn’t resolved the issue.
The most common cause of lipohypertrophy is receiving multiple injections in the same area of skin over an extended period of time. This is mostly associated with conditions like type 1 diabetes and HIV, which require multiple injections of medication on a daily basis.
There are several factors that increase the odds of developing lipohypertrophy. The first is receiving injections at the same location too often, which can be avoided by consistently rotating your injection sites. Using a rotation calendar can help you keep track of this.
Another risk factor is reusing the same needle more than once. Needles are meant to be single-use only and are dulled after each use. The more you reuse your needles, the greater your chance of developing this condition. One study found that 46 percent of people who developed lipohypertrophy reused needles. Poor glycemic control, duration of diabetes, needle length, and duration of insulin therapy are also risk factors.
Tips for preventing lipohypertrophy include:
- Rotate your injection site each time you inject.
- Keep track of your injection locations (you can use a chart or even an app).
- Use a fresh needle each time.
- When injecting near a previous site, leave about an inch of space in between the two.
Also, keep in mind that insulin absorbs at different rates depending on where you inject. Ask your doctor if there’s a need to adjust your meal timing for each site.
In general, your abdomen absorbs injected insulin the fastest. After that, your arm absorbs it most quickly. The thigh is the third fastest area for absorption, and the buttocks absorb insulin at the slowest rate.
Make it a habit to routinely inspect your injection sites for signs of lipohypertrophy. Early on, you may not see the bumps, but you’ll be able to feel the firmness under your skin. You may also notice that the area is less sensitive and you feel less pain when you inject.
When to call a doctor
If you notice that you’re developing lipohypertrophy or suspect that you might, call your doctor. Your doctor might change the type or dosage of insulin that you use, or prescribe a different type of needle.
Lipohypertrophy can affect the way your body absorbs insulin, and it may be different than what you expect. You may be at increased risk for hyperglycemia (high blood glucose levels) or hypoglycemia (low blood glucose levels). Both are serious complications of diabetes. Because of this, it’s a good idea to test your glucose levels if you’re receiving an insulin injection in an affected area or in a new area.