Familial Mediterranean Fever – Symptoms and Causes

Overview

Familial Mediterranean fever affects people from Mediterranean backgrounds but can appear in any ethnic group. This genetic condition causes repeated fever episodes and painful inflammation in the abdomen, chest, and joints.

While FMF has no cure, most patients working with specialists can achieve good symptom control with proper treatment.

Symptoms

Familial Mediterranean fever (FMF) generally starts during childhood. The condition causes episodes called attacks that typically last 1-3 days, though joint-related attacks may continue for weeks or months.

FMF attacks can include several symptoms:

• High temperature
• Pain in the stomach area
• Chest discomfort that may make breathing difficult
• Painful, swollen joints (mainly knees, ankles, hips)
• Muscle aches and soreness
• Fatigue or tiredness
• Reddish skin rash on the legs, particularly below the knees
• Swelling and tenderness in the scrotum

These symptoms usually go away on their own after a few days. Between attacks, people often return to feeling normal. The time between episodes varies greatly—from days to years.

When to See a Doctor

Contact your health care provider right away if:

• A sudden fever occurs with pain in the abdomen
• Chest pain accompanies a fever
• Joint pain develops along with a fever

These symptoms may signal a serious condition that needs medical attention.

Causes

Familial Mediterranean fever (FMF) stems from genetic mutations passed down through families. These mutations affect the MEFV gene, which controls a protein called pyrin. When pyrin doesn’t work properly, the body can’t regulate inflammation correctly.

Scientists have identified numerous mutations in the MEFV gene linked to FMF. The severity of symptoms often depends on which specific mutation a person inherits. Some genetic changes cause mild symptoms, while others lead to more serious disease.

Several factors may trigger FMF attacks:

• Emotional stress
• Menstrual periods
• Cold exposure
• Physical stress (illnesses or injuries)

The exact trigger mechanism remains unclear, but these factors seem to set off the inflammatory response in people with the genetic mutation.

Risk Factors

Several factors can raise your chances of developing familial Mediterranean fever:

• Family History: Having relatives with FMF significantly increases your risk of developing this condition.
• Ethnic Background: While FMF can affect anyone, it appears more frequently in people with ancestry from:
  • Jewish communities
  • Arab regions
  • Armenia
  • Turkey
  • North Africa
  • Greece
  • Italy

People with Mediterranean heritage generally face higher risks of developing this genetic disorder, though it can occur in any ethnic group.

Complications

Without proper treatment, familial Mediterranean fever (FMF) can lead to several serious complications. Inflammation from this condition affects multiple body systems.

Patients may develop amyloidosis when their bodies produce excess amyloid A protein during FMF attacks. This protein can build up in organs and cause damage over time.

The kidneys are particularly vulnerable to amyloidosis damage. This can result in nephrotic syndrome, where the kidney’s filtering systems become impaired.

People with this condition often lose significant amounts of protein in their urine. This may lead to kidney failure or blood clots in the renal veins.

Joint problems are common with FMF. Many patients experience arthritis, especially in the knees, ankles, and hips.

Reproductive health can also suffer. The ongoing inflammation may affect reproductive organs and cause infertility in some cases.

Other possible complications include:

• Heart inflammation
• Lung inflammation
• Spleen inflammation
• Brain inflammation
• Inflammation in superficial veins

Early diagnosis and consistent treatment help reduce the risk of these complications.