Sarcoidosis

What happens in sarcoidosis

In sarcoidosis, the immune system overreacts to an unknown trigger and forms granulomas, small, organized clusters of immune cells. In many people they clear on their own. In others, they persist and can scar (fibrose) the affected organ.

Causes and risk factors

The cause is unknown. It likely results from an immune response to an environmental exposure in genetically susceptible people. Associations include:

• exposure to dusts, molds, insecticides, metal or wood dust; firefighters and World Trade Center responders had higher rates
• certain gene variants (HLA types)
• family history
• age 20 to 60, slightly more common in women
• Black Americans have a higher rate and more often severe, chronic disease

Sarcoidosis is not contagious and is not cancer.

Symptoms by organ

Lungs and chest

• dry cough
• shortness of breath
• chest discomfort
• swollen lymph nodes in the chest on imaging, often without symptoms

Skin

• erythema nodosum: tender red lumps on the shins
• lupus pernio: purplish patches on the nose, cheeks and ears
• small bumps, plaques, and changes in old scars or tattoos

Eyes

• uveitis: red, painful eyes, light sensitivity, blurred vision
• dry eyes

Other organs

• Heart: rhythm problems, heart block, heart failure, sudden death (cardiac sarcoidosis)
• Nervous system: facial palsy, headaches, seizures, nerve problems
• Joints: ankle swelling and pain
• Liver and spleen: enlargement, abnormal liver tests
• Kidneys: high calcium and kidney stones
• General: fatigue, fever, weight loss, night sweats

Löfgren syndrome

An acute form with erythema nodosum, swollen chest lymph nodes, fever and ankle arthritis. It usually resolves within 1 to 2 years and has an excellent outlook.

Stages of lung sarcoidosis

Chest x-ray stages (Scadding) help describe lung involvement:

Diagnosis

There is no single test. Diagnosis requires:

1. compatible clinical and imaging features: chest x-ray, high-resolution CT
2. biopsy showing non-caseating granulomas, often from lymph nodes via bronchoscopy with endobronchial ultrasound (EBUS), or from skin
3. exclusion of other causes, especially tuberculosis, fungal infections and lymphoma

In typical Löfgren syndrome, biopsy may not be needed.

Screening other organs

• eye exam by an ophthalmologist
• ECG for everyone; heart monitoring, echocardiogram, cardiac MRI or PET if heart involvement is suspected
• blood calcium, kidney and liver function, urine calcium
• lung function tests

Treatment

Many people do not need treatment, especially those with mild lung disease or Löfgren syndrome. Treatment is recommended when sarcoidosis threatens organ function or causes significant symptoms.

• Corticosteroids (such as prednisone): first-line; usually started at a moderate dose and tapered over months.
• Steroid-sparing medicines: methotrexate, azathioprine, leflunomide or mycophenolate for long-term control.
• TNF inhibitors (infliximab, adalimumab) for severe, refractory, cardiac, neurological or skin disease.
• Topical or injected steroids for skin and eye involvement.
• Pacemaker or defibrillator for cardiac sarcoidosis with rhythm problems.
• Oxygen, pulmonary rehabilitation, and lung transplant for advanced fibrosis.
• Fatigue management, exercise and support.

Outlook

• Up to half of people recover within 2 to 3 years, often without treatment.
• About a third have chronic disease that may need long-term treatment.
• A minority develop serious lung fibrosis, heart or nervous system involvement, which are the main causes of death.

Regular follow-up is important even when symptoms settle.

Frequently asked questions

What is sarcoidosis?

Sarcoidosis is an inflammatory disease in which clusters of immune cells called granulomas form in organs, most often the lungs and chest lymph nodes. It can also affect the skin, eyes, heart and nerves. Many cases resolve without treatment.

What are the first symptoms of sarcoidosis?

Common early symptoms include a persistent dry cough, shortness of breath, fatigue, red bumps on the shins, red or painful eyes and joint pain, especially in the ankles. Many people have no symptoms and are diagnosed after a chest x-ray.

Is sarcoidosis serious?

Often it is mild and goes away by itself. However, it can cause lasting lung scarring or serious heart, eye or nervous system problems in some people. Regular monitoring helps catch and treat these complications early.

What is the life expectancy with sarcoidosis?

Most people with sarcoidosis have a normal or near-normal life expectancy. Outcomes are worse for people with advanced lung fibrosis, cardiac sarcoidosis or neurosarcoidosis, which need specialist treatment.

Can sarcoidosis go away on its own?

Yes. Up to half of people, particularly those with Löfgren syndrome or only swollen chest lymph nodes, recover within a few years without treatment. Others need medicines to control the inflammation.