26th February 2025

Familial Mediterranean fever (FMF)

This is an autosomal recessive disease caused by a mutation in the MEFV gene, which encodes the pyrin protein. Diagnosis is by genetic testing.

It is most common in Mediterranean populations. Onset is generally in childhood, with 90% of patients experiencing an attack before the age of 20.

Episodes of fever and serositis characterise the disease. These can occur at a varying frequency and generally last up to 72 hours. Symptoms will depend on the site of inflammation; for example, abdominal pain mimicking an acute abdomen can occur with peritonitis and chest pain can be caused by pericarditis or pleuritis. Arthritis is also a common symptom. This is generally monoarticular, affecting the large joints. 

Treatment is with oral colchicine. This helps to prevent flares and decrease the risk of the development of complications such as amyloidosis. IL-1 inhibitors such as anakinra and canakinumab are starting to be used in colchicine-refractory cases.