What to Know About Panniculitis

Panniculitis is a catch-all term to describe inflammation of the fatty layer underneath the skin's surface.

It causes inflamed lumps and plaques (broad, raised areas) on the skin, which range in size from several millimeters to several inches across. In the majority of cases, these lumps are painful. It can occur anywhere on the body but is most commonly found on the lower legs and feet.

In this article, learn more about panniculitis, including symptoms and causes. It also discusses diagnosis and forms of treatment.

What Is Panniculitis?

Humans have three main layers of skin: the epidermis, the dermis, and subcutaneous tissue. The epidermis is the uppermost layer, the layer we see every day. The dermis is just below and holds our oil glands, sweat glands, hair follicles, and bulbs. The deepest layer, the subcutaneous tissue, protects our body.

Anyone, at any age, can develop panniculitis, but it tends to be more common in women.

Symptoms of Panniculitis

The most notable indicator of panniculitis is tender lumps underneath the skin. You may have just one lump or a cluster of them. They may feel like knots or bumps under the skin or be broader, raised swellings called plaques. Sometimes, the swellings drain oily fluid or pus.

The most common place for panniculitis is the lower legs (shins and calves) and feet. However, it can develop in other areas of the body, including the hands and arms, thighs, buttocks, abdomen, breasts, or face. It's much less frequently found in those areas, though.

You may also have a fever and feel run-down or tired. Joint or muscle aching, stomach pain, and nausea or vomiting can also occur. These symptoms can sometimes appear even before the swellings do.

Panniculitis can also cause dark discolorations on the skin that look like bruising. These typically will fade over time once the inflammation recedes. In some cases, it can also leave depressed areas on the skin. This happens if the tissue beneath has to be destroyed. These depressed areas may improve with time, but they're often permanent.

What Is the Cause of Panniculitis?

Panniculitis isn't caused by any specific condition; instead, many conditions can cause inflammation of the subcutaneous tissue. It may take some sleuthing to determine precisely what is causing your panniculitis.

• Infection is likely the most common cause of panniculitis. Bacteria, viruses, fungi, and even parasites can trigger panniculitis development. And it's not just infection involving the skin tissue. An infection like strep throat or tuberculosis can cause panniculitis.
• Injury to the skin, either by trauma or cold, can also cause panniculitis. This is more likely to happen in areas with lots of fatty tissue, like the breast or buttocks. It doesn't always have to be a hard blow to the area; something as simple as an injection could do it. Frigid temperatures can cause panniculitis in exposed skin (called cold panniculitis).
• Certain medications can also trigger its development. Some of the bigger offenders are sulfonamide antibiotics, birth control pills, estrogen, and large doses of corticosteroids.

Other causes of panniculitis can include:

• Diabetes
• Inflammatory conditions like Crohn's disease and ulcerative colitis
• Connective tissue disorders like lupus or rheumatoid arthritis
• Alpha 1–antitrypsin deficiency
• Certain cancers like leukemia and lymphoma
• Pancreatic disease
• Pregnancy
• Sarcoidosis

In many cases, a specific cause isn't identified. This is called idiopathic panniculitis.

Diagnosing Panniculitis

Panniculitis can be diagnosed by visual inspection. A biopsy is often done to confirm the practitioner’s assessment. Your healthcare provider may also swab your throat to check for infections like strep and do a chest X-ray to look for things that may be triggering panniculitis, like tuberculosis.

Not all skin lumps are panniculitis. Many other conditions can cause painful lumps and bumps underneath the skin’s surface: cysts and boils, deep acne lesions (acne nodules or cysts), folliculitis, and more.

It’s important not to try to self-diagnose. Unidentified lumps and bumps on the skin should always be inspected by a healthcare provider. Panniculitis can be a sign of something more serious, especially when it develops with other symptoms.

There are many types of panniculitis, but the most common form is erythema nodosum. This type of panniculitis affects the lower legs, mainly the shins, although it sometimes can happen on the calves and thighs. Other types of panniculitis are incredibly rare.

Because so many things can cause panniculitis, getting a specific diagnosis can sometimes be challenging. You may never know precisely what is causing your panniculitis.

What Is the Best Treatment for Panniculitis?

The treatment for panniculitis varies depending on what is causing the condition. Just like there isn't one sole cause of panniculitis, there isn't one specific go-to treatment for the problem. Because many different conditions can cause panniculitis, treatment will vary from person to person.

You aren't treating the panniculitis itself; there is no specific treatment for panniculitis. The focus is treating the underlying cause of panniculitis and easing symptoms to make you more comfortable.

Anti-inflammatory painkillers like ibuprofen can help lessen the swelling and make them feel less tender. Your healthcare provider may also prescribe antibiotics if you have a bacterial infection. Immunosuppressants, corticosteroids, and chemotherapy treatments may be used in severe, long-lasting cases.

Most cases of panniculitis will heal completely even without treatment, although it can last anywhere from a few weeks to a few months before subsiding. Until then, keeping the area elevated when possible can help with inflammation, as can cold compresses. Try compression stockings if panniculitis is on the legs.

If panniculitis was caused by trauma, it's highly unlikely to reoccur (unless you reinjure the area again). For inflammation triggered by other causes, though, or in cases where a specific cause isn't identified, panniculitis is often recurring.

Summary

To the untrained eye, many skin problems mimic panniculitis. This is why it’s so important to get a proper diagnosis. Also, because panniculitis can be a sign of something more serious, you do want to be seen by a healthcare provider.

Panniculitis can come and go, which can be frustrating especially if it has no clear cause or trigger. Work closely with your healthcare provider to come up with a plan to control or minimize the flare-ups. Most importantly, take it easy on yourself, and get plenty of rest to allow your body to heal.