Definition and Overview

Also known as sarcoidosis, sarcoid is a disease that involves the abnormal growths of groups of inflammatory cells, also known as granulomas, that form nodules in various organs in the human body. In most cases of sarcoid, the granulomas gather in the lungs, or the lymph nodes associated with this organ. However, any organ in the body can be affected by the growth of these inflammatory cells.

Granulomas usually manifest as small patches of swollen, reddish tissues, which could also manifest in the skin.

Many cases of sarcoid can be resolved without any medical intervention, but more severe cases can lead to serious complications that can become life-threatening over time.

Though this disease can affect all races and age groups, many patients in the United States fall under Icelandic, Scandinavian, or African ethnicities, ranging from the ages twenty to 29. In the United Kingdom, researchers place the number of affected patients at one for every 10,000. Women are at higher risk of contracting the disease. In developing countries, patients suffering from sarcoidosis are often misdiagnosed with tuberculosis since these two diseases share some similar symptoms.

Over time, sarcoidosis can cause serious complications, as the granulomas can alter the structure and functions of the affected organs.

Cause of Condition

Up to this day, the exact cause of sarcoidosis is still unknown. However, there are several hypotheses that propose several causes of the disease, as well as how it spreads across different parts of the body.

One of the factors that is being considered as the primary cause is genetics. Research suggests that race plays a major role in the development of this disease. Twenty percent of African-American sarcoid patients have close family members suffering from the same condition while only five percent of white patients have the disease in the family. Researchers have pursued this lead to identify if there are certain genetic markers that increase the risk of sarcoidosis. Unfortunately, the research has failed.

Infectious agents are other possible factors that researchers are looking into. Research shows that sarcoidosis can be caused by various infectious agents, such as rickettsia, mycobacteria, borrelia, and fungi. Research also shows that sarcoidosis can be transmitted to different individuals through organ transplantation such as kidney transplant.

There is also a medical literature that declares the body’s autoimmune functions as the culprit for the development of the disease. When the body releases white blood cells to fight off an infection, or isolate and attack bacteria or viruses, the natural result is the inflammation of tissues in the affected area. The immune system is designed to respond to any threat that enters the body, and the process will end on its own once the infection has been successfully fought off.

Some researchers believe that the immune system going haywire is the reason for sarcoidosis; white blood cells start attacking the patient’s own tissues and organs, resulting to an inflammation that is not actually helpful to the body’s health. This unnecessary inflammation causes the development of granulomas in various parts of the body.

None of these hypotheses has been proven so far, but many medical professionals agree that a combination of these factors can indeed result to sarcoidosis. Individuals with a genetic predisposition to the disease can develop it once exposed to certain environmental factors.

Key Symptoms

Sarcoid can affect different organs in the body, and symptoms depend on the location of the granulomas. However, there are common symptoms to watch out for, such as fatigue that is not resolved by rest or sleep, weight loss, a general lack of energy, pain in the joints, arthritis, shortness of breath, frequent dry coughing, skin lesions, swollen knees, dry eyes, and blurry vision. The most common symptom, however, is the presence of small bumps and rashes on the skin.

Below are common symptoms of the condition when affecting specific body parts:

  • Lungs (or the respiratory tract, in general) - 90% of sarcoid patients have granulomas in their respiratory track, making this the most common type. Granulomas in the lungs can inflame the small blood vessels, the small bronchi, and the alveoli, which could lead to impaired function of the respiratory tract. Common symptoms include wheezing, shortness of breath, persistent dry cough, and chest pains. More severe cases can cause pulmonary fibrosis.

  • Skin - Sarcoid in the skin involves visible lesions and rashes. Lesions are commonly found on the ears, cheeks, and nose, which could eventually disfigure the patient’s face. Rashes are commonly located on the ankles and shins, and are usually warm and tender when touched. Various parts of the skin can also change color, and the patient can develop nodules under or around scars.

  • Eye - Sarcoidosis in the eyes typically remains undiagnosed, because it does not usually cause symptoms that alarm the patient. In cases when the patient can observe symptoms, sarcoid in the eyes can cause pain, severe redness of and around the eye, unusual sensitivity to light, and blurry vision.

Other symptoms include swelling and pain in the joints, tender, enlarged lymph glands in the armpits, neck, and groin, uncharacteristically hoarse voice, pain in the hands or feet due to cysts in the bones, an enlarged liver, the formation of kidney stones, pericarditis, arrhythmias, hearing loss, depression, meningitis, seizures, psychosis, and dementia.

Who to See and Types of Treatment Available

As mentioned earlier, many cases of sarcoidosis can go away on their own usually several months or years after the symptoms have first manifested.

In the case of minor to moderate pain, the patient can turn to over-the-counter pain medication such as ibuprofen or paracetamol. General practitioners can also prescribe regular monitoring to ensure that the disease does not worsen over time.

Reducing inflammation, lesions, and rashes on the skin can be addressed by prescription corticosteroid tablets, which can also manage other symptoms. However, steroid medication should only be taken for a short period to reduce the risk of negative side effects, such as weight gain, mood swings, and weakening of the bones.


  • Aminoff MJ, Josephson SA. Neurological complications of systemic disease: adults. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 49A.

  • Iannuzzi M. Sarcoidosis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 95.

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