Blau syndrome is a rare inflammatory disease that can lead to rashes, arthritic joints, and eye diseases. Most cases of this condition are inheritable through families, but some develop due to a genetic mutation.

This article will explore what Blau syndrome looks like, when symptoms usually begin, and how you can manage and treat this chronic condition.

Blau syndrome is a rare disease, impacting less than 1,000 people in the United States. Symptoms usually appear in newborns and infants who inherit the genetic variation that causes the disease from one of their parents.

Although most cases of Blau syndrome take on this inheritable form, there is also a sporadic form of the disease that appears in people with no family history. This variation is called early-onset sarcoidosis. Both of these conditions are autoinflammatory diseases that target the skin, joints, and eyes.

For most people with the inheritable form of this disease, Blau syndrome symptoms appear in the first few years of life, typically when the child is around 3 or 4 years old.

The main reason for the early appearance of the disease is that family members can pass it down to each other as a NOD2 gene mutation. It’s possible for symptoms to appear even after 10 years old, but the most common range is between 4 months and 5 years old.

The first symptoms that appear with Blau syndrome involve arthritic swelling or pain in one or more joints, and a rash or raised bumps under the skin.

There is currently no cure for the disease, so symptoms progress to impact more joints and other body parts.

Blau syndrome isn’t necessarily a fatal disease, but different symptoms can lead to complications with pain or infection, which may impact quality of life.

There are medications to slow or manage symptoms and the progression of Blau syndrome, but treatment effectiveness varies from person to person.

Arthritic pain, or articular involvement, is one of the first symptoms to appear with Blau syndrome, and it’s present in nearly every person who has this disease. It affects a wide range of joints, including:

  • wrists
  • knees
  • ankles
  • fingers
  • elbows
  • hips
  • spine

In terms of how disabling this damage can be, one small 2014 study estimated that 41% of people could still perform their usual daily activities. Nearly 50% experienced mild to moderate disability. Severe impairment occurred in about 11% of people with Blau syndrome, according to the study.

The appearance of skin rashes is also common in people with Blau syndrome. These rashes may usually appear as:

  • red and raised
  • scaly and dry
  • tan-colored and scaly
  • a white scaly covering on the skin

Raised, reddish nodules may also appear with Blau syndrome, but this is a less common symptom.

While rashes and joint pain or inflammation are the most common symptoms of Blau syndrome, these can lead to more severe damage and disability over time.

One of the most common complications of Blau syndrome is eye problems, usually in the form of redness and inflammation of the middle layer of the eye. As many as 80% of people with Blau syndrome develop eye problems that can include:

The gene variation that causes Blau syndrome mostly affects the skin, joints, and eyes, but this condition can also lead to problems with certain blood vessels or internal organs. Some of the less common, but still possible, ways Blau syndrome can impact other areas of the body include:

There are some aspects of Blau syndrome that doctors can see during a physical examination, but many of the symptoms that appear with this disease are similar to various other conditions.

Genetic testing or a prior knowledge of Blau syndrome passing through a family may help speed a diagnosis, but doctors usually diagnose this condition with a combination of the following tests.

  • blood testing for inflammation in the body
  • skin biopsies to check for inflammation and granulomas
  • imaging studies, like X-rays, to examine bone and joint changes

There is currently no cure for Blau syndrome, but there are treatments that can help you manage symptoms like pain and inflammation. Depending on your symptoms and the complications you develop with Blau syndrome, you may be able to slow the progression of the disease to minimize its effect.

The rarity of Blau syndrome combined with the wide range of symptoms that can appear make treating the condition difficult. Your doctor will need to tailor your medications and treatment to your symptoms and complications and consider any other health conditions you may have.

The most common way of treating Blau syndrome is with systemic medications that suppress your immune system to reduce inflammation. Treatment can include medications like:

Newer biologic medications that work to target specific areas of your immune system can also treat Blau syndrome. Examples of medications that a doctor may prescribe to treat this condition include:

  • etanercept
  • tocilizumab (Actemra)
  • adalimumab
  • infliximab
  • canakinumab (Ilaris)
  • anakinra (Kineret)

Blau syndrome is a rare disease that causes arthritis symptoms, like pain and form changes in the joints, skin rashes and discoloration, and eye problems. Although some cases occur due to a genetic mutation, most people with Blau syndrome inherit it from genes their parents pass on, so symptoms begin in infancy or childhood.

There is currently no cure for Blau syndrome, but medications that suppress the immune system and manage inflammation can help calm symptoms and slow the progression of the disease.