Familial Mediterranean fever: an animated, cited guide

This page needs JavaScript for its animations. The outline and key answers are below, and every claim in the full version carries a numbered citation.

Not medical advice. FMF Companion is an educational synthesis of published literature. It does not replace a clinician.

What is in it

What FMF is Who gets it, the numbers, and what an attack looks like.
The gene and inheritance MEFV, pyrin, the common variants and an animated Punnett square.
Pyrin, animated How pyrin guards RhoA, and what FMF variants change.
An attack, hour by hour 72 hours of fever, pain, CRP and SAA, site by site.
Colchicine inside the cell From the pill to the neutrophil to the microtubule.
Colchicine over months Why the benefit builds slowly, and what it prevents.
Dosing, safety and interactions What the guidelines and the label publish.
AA amyloidosis Serum amyloid A to fibril to kidney, over years.
Diagnosis and criteria Tel Hashomer, Livneh and the Eurofever/PRINTO calculator.
The differential TRAPS, MKD, CAPS, PFAPA, Behçet and the surgical abdomen.
The treatment ladder Colchicine first, then IL-1 blockade.
Living with FMF Pregnancy, surgery, school, triggers and monitoring.
Toward a cure What a cure would need, and the evidence for each route.
History and people 1908 to the discovery that pyrin senses RhoA.
Flashcards, quiz and glossary Revision for students.
Sources Every reference behind the app.

Part 3 · Complications & diagnosis

The differential

Recurrent fever with pain has many causes. The rhythm is often the first clue: how long each episode lasts, how regularly it comes back and whether it ends by itself. Press play to sweep through 60 days, then click a disease to see how it is told apart.

Across the hereditary recurrent fevers, how long an episode lasts is the single most discriminating variable: FCAS under a day, FMF 1–3 days, PFAPA 3–6 days, MKD 3–7 days, TRAPS 7 days or more. The FMF, PFAPA, MKD and TRAPS lengths are cited in the table below; the FCAS figure is standard teaching, not tied to a fetched source. ^{62,75,144,258}

Pick a disease

Day

febrile episodeulcersusually afebrilechronic activityprogressive, surgical

Schematic 60-day window. Episode lengths follow the sources in the table; the spacing is illustrative. The right-hand tag says whether a row's rhythm is cited ("cited") or comes from standard teaching not tied to a fetched source ("teaching").

Fever + abdominal pain: decision points

Pick a clue from the story. The matching rows light up in the animation above and the box below names the test that separates them.

Exam hookFever + abdominal pain, four questions: Does it stop by itself in 1–3 days? (FMF). Is it getting worse and moving to the right lower quadrant? (appendicitis, even in FMF). Is there fever at all? (porphyria usually has none). What is the rhythm? FMF irregular, PFAPA clockwork every ~4 weeks, TRAPS a week or more, Still's disease daily spikes. Then: ferritin flat in FMF, very high in Still's. ^{4,136,150,258,277}

In plain wordsMany illnesses cause fever and tummy pain. Doctors tell them apart mainly by how long each bout lasts, how often it comes back, what else happens at the same time, and a few targeted tests. An FMF attack stops on its own within a few days; appendicitis keeps getting worse.

The full comparison

Click any row to load it into the note panel above.

Disease	Gene / inheritance	Typical attack length	Key distinguishing features	Distinguishing test