What is Familial Mediterranean Fever?
Familial Mediterranean fever (FMF) is an inherited condition which causes episodic attacks of fever and painful inflammation of the abdomen, chest, and joints. People with FMF may also develop a rash during these attacks. The attacks last for 1 to 3 days and can vary in severity. Between attacks, the person typically feels normal. These symptom-free periods can last for days or even years.
In 80-90% of people affected by FMF, the first attack occurs by the age of 20. Less commonly, symptoms begin later in life. Children who have FMF may experience periodic fever as their only symptom.
Some people with FMF develop a protein buildup in various parts of the body, notably the kidney. If left untreated, this can lead to life-threatening kidney failure. People who do not experience the characteristic attacks of FMF can still develop this particular form of kidney failure. This symptom is most common among people of Turkish and North African Jewish heritage, affecting 60% and 75% respectively.
Other symptoms that can occur during an attack of FMF include headache and inflammation of the heart and/or testicles. Affected people may also develop an inflammation of the membrane that surrounds the brain and spinal cord, though this is not usually serious or damaging. People with FMF who go untreated may experience decreased fertility.
About half of people with FMF have mild symptoms preceding an attack. These may include a mild, unpleasant sensation in parts of the body that will soon be affected or may consist of other physical and emotional symptoms.
How common is Familial Mediterranean Fever?
FMF is most common among ethnic groups from the Mediterranean region, notably people of Armenian, Arab, Turkish, Iraqi Jewish, and North African Jewish ancestry. One in every 200 to 1,000 people in these groups is affected by the disease and carrier rates in some populations have been estimated as high as 1 in 5.
Cases of FMF have also been found in other populations, including Italians, Greeks, Spaniards, Cypriots, and less commonly, Northern Europeans and Japanese.
How is Familial Mediterranean Fever treated?
There is no cure for FMF, however the drug colchicine has been very effective in preventing the disease’s characteristic attacks. With daily doses of colchicine, 75% of people with FMF can avoid attacks with an additional 15% showing an improvement in their symptoms. Colchicine also prevents the dangerous buildup of proteins in the kidneys which could otherwise lead to kidney failure.
Episodic attacks of fever and inflammation can be treated with non-steroidal anti-inflammatory drugs. Those who do develop serious kidney failure may be helped by kidney transplantation.
What is the prognosis for a person with Familial Mediterranean Fever?
With early and regular treatment, people with FMF can live a normal lifespan and may even be symptom-free. The disease has the potential to be life-threatening only if the person is untreated (or does not respond to treatment) and develops kidney failure.