If you’re new to using an injectable medication for eczema at home, it can be hard to know what’s normal and what isn’t. Although a lump at the injection site isn’t a common side effect, you should be aware of what can cause it, when you should contact your doctor, and how to prevent it.

Injectables for Eczema

Your dermatologist may prescribe an injectable for eczema if you have uncontrolled moderate to severe atopic dermatitis (the most common subtype of eczema) or if you can’t use other treatment options.

Prescription injectables for eczema belong to a class of medications called biologics. Biologic therapy uses human-made proteins called monoclonal antibodies to target specific parts of the immune system. The U.S. Food and Drug Administration (FDA) has approved two injectable medications to treat eczema:

• Dupilumab (Dupixent) — For use in adults and children 6 months and older
• Tralokinumab-ldrm (Adbry) — For use in adults

Dupilumab and tralokinumab-ldrm block immune proteins called interleukins (ILs), which can cause skin inflammation and decrease the barrier (protective) function of skin affected by eczema. Dupilumab blocks two specific interleukins, IL-4 and IL-13, whereas tralokinumab-ldrm blocks only IL-13.

Both medications are given subcutaneously (beneath the skin). You can inject these medications on your own at home or in your doctor’s office.

Common Side Effects of Biologics for Eczema

Redness, itching, and swelling at the injection site are among the most common side effects of biologics for eczema. Eye problems such as conjunctivitis (pink eye), dry eye, and blepharitis (eyelid inflammation) are common side effects, too.

Dupilumab is also associated with an increased risk of developing oral herpes (cold sores). Tralokinumab-ldrm can cause other side effects like upper respiratory tract infections (such as the common cold) and high levels of eosinophils (a type of white blood cell).

Several MyEczemaTeam members shared that they didn’t experience any side effects with dupilumab. “I have Dupixent injections … every two weeks — no side effects,” one member said.

What Can Cause a Lump at the Injection Site?

Lumps aren’t listed as a possible side effect of either drug. However, some of the other side effects of biologics could cause you to feel a lump at or near the injection site.

Wheal Formation

If you notice a raised area of skin immediately after your injection, it could be a wheal (welt). A wheal can result when injected liquid medication causes the skin to rise. It may take some time for the medication to be absorbed into your bloodstream after it’s injected.

For most people, this effect should fade within a few hours after the injection. If the wheal doesn’t go away, talk to your doctor.

Injection Site Reaction

Injection site reactions are one of the most common side effects of injectables for eczema. In clinical trials, injection site reactions occurred in about 10 percent of people using dupilumab and about 7 percent using tralokinumab-ldrm.

Injection site reactions are localized, which means the side effect is limited to the area around the injection, not your whole body. The symptoms of an injection site reaction include:

• Redness
• Pain
• Bruising
• Swelling
• Itching

You may notice these symptoms shortly after your injection, and they can last three to five days.

Let your doctor know if your symptoms don’t get better after a few days or if they worsen. For example, if the injection site starts to drain fluid or pus or if the area feels warm to the touch, you may have developed an infection.

Lipohypertrophy

If you notice a lump of fatty tissue under your skin in the same place that you usually inject your medication, you may have lipohypertrophy. An area affected by lipohypertrophy may feel firmer than the tissue around it and be:

• Lumpy
• Raised
• Thick
• Rubbery
• Swollen
• Numb

Lipohypertrophy can be caused by injecting medication into the same area of the skin too often. Your body may react to too many injections in one place by causing a buildup of fat and scar tissue.

Although lipohypertrophy usually doesn’t spread, the lump can get bigger over time if you continue to inject in the same place. You may also find lumps in other areas you inject.

There isn’t any information about how often lipohypertrophy may occur in people using biologics for eczema. However, this skin disorder is common in people with diabetes who inject insulin subcutaneously every day.

A lump caused by lipohypertrophy shouldn’t feel painful or hot to the touch. If you have these symptoms or notice any bruising or redness in the area, you should seek medical advice right away.

Treatment for Lumps at the Injection Site

Your treatment will depend on what’s causing the lump. If the lump is caused by an injection site reaction, your doctor may recommend supportive treatments. You can take antihistamines to help control rashlike symptoms such as redness and itching.

If you have any pain, your doctor may recommend a pain reliever, like acetaminophen (Tylenol). Applying an ice pack or cold compress may also provide relief.

If a lump is caused by a skin infection, you may need to take a course of antibiotics. Some types of lumps, such as wheals or lipohypertrophy, may not call for any specific treatment.

Preventing Lumps at the Injection Site

Try the following tips to help prevent lumps at the injection site:

• Study the materials that came with your medication to make sure you understand the proper administration technique. Ask for help from your doctor, nurses, or pharmacist if you have any questions.
• Rotate your injection site, alternating spots around your belly button and thighs.
• Practice good hygiene. Prevent infections by washing your hands with soap and water and cleaning the area with alcohol before you inject.

Other Treatment Options

If you experience bothersome side effects with an injectable medication for eczema, talk to your doctor about other options. You may need to stop or change medications if you have an allergy or other adverse reactions to injectable medications. Alternative prescription treatment options for moderate to severe eczema include:

• Topical corticosteroids, such as betamethasone valerate (Luxiq), fluticasone (Cutivate), and triamcinolone (Kenalog)
• Topical calcineurin inhibitors, such as tacrolimus (Protopic) and pimecrolimus (Elidel)
• Immunosuppressants, such as azathioprine (Imuran), cyclosporine (Gengraf, Neoral, Sandimmune), methotrexate (Rheumatrex, Trexall), and mycophenolate mofetil (CellCept)
• JAK inhibitors, such as abrocitinib (Cibinqo) and upadacitinib (Rinvoq)
• Phototherapy (light therapy)
• Oral corticosteroids, such as prednisone (Deltasone)

Your health care provider can help you find the treatment plan that will help you achieve the best results with the fewest side effects.

Talk With Others Who Understand

MyEczemaTeam is the social network for people with eczema and their loved ones. On MyEczemaTeam, more than 49,000 members come together to ask questions, give advice, and share their stories with others who understand life with eczema.

Have you felt a lump where you inject your medication? Have you taken steps to keep lumps from forming at your injection site? Share your experience in the comments below, or start a conversation by posting on your Activities page.