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Autoimmune & autoinflammatory

TRAPS

TNF receptor-associated periodic syndrome (TRAPS) causes fever episodes lasting one to three weeks - far longer than other periodic fevers - with migrating muscle pain, rash and eye inflammation.

Key points

The essentials at a glance.

What to look out for, which tests matter, who treats it, and what usually happens next.

  • Distinguishing feature: attack length - typically 1 to 3 weeks, versus 1-3 days in FMF

  • Classic accompaniments: migrating muscle pain with overlying red rash, painful red eyes or periorbital swelling, abdominal pain

  • Autosomal dominant: fever syndromes often run visibly through one side of the family

  • Diagnosis is confirmed by TNFRSF1A gene testing

  • IL-1 blockade has become the cornerstone for frequent attacks; untreated lifelong inflammation risks amyloidosis

Understanding it

About TRAPS.

TRAPS attacks unfold like a slow storm: fever building over days, a deep cramping muscle pain that migrates centrifugally down a limb with a blanching red rash tracking above it, one or both eyes red and swollen, belly pain that has taken more than one patient to theatre for a normal appendix. Then, after one, two or three weeks, it recedes - until the next episode, weeks or months later. The dominant inheritance means an affected parent, aunt or grandparent with the same unexplained fevers is often hiding in the family history.

Genetic confirmation matters because it unlocks precise treatment: short steroid courses can truncate occasional attacks, but frequent or severe disease now standardly earns interleukin-1 blockade, which prevents episodes and - the long-game justification - protects against AA amyloidosis, the kidney-destroying consequence of decades of unchecked inflammation. Care sits naturally in a specialist autoinflammation centre with monitoring of inflammatory markers even between attacks, since subclinical inflammation counts toward that amyloid risk. In many parts of the UK, a routine NHS referral to the relevant specialist clinic currently means waiting many months - sometimes more than a year for the rarest conditions - whereas an initial appointment with a private consultant is typically available within around two weeks, with investigations arranged soon after.

Frequently asked

Common questions about TRAPS.

Quick, plain-English answers to what people ask us most.

  • What is TRAPS?

    TRAPS (TNF receptor-associated periodic syndrome) is a rare genetic autoinflammatory condition causing recurrent episodes of fever, along with abdominal pain, muscle pain, rash and eye inflammation, due to a faulty TNF receptor gene.

  • What causes TRAPS?

    It is caused by a mutation in the TNFRSF1A gene, which disrupts normal control of inflammation, leading to episodes of excessive inflammatory activity.

  • What are the symptoms of TRAPS?

    Recurrent fever episodes lasting days to weeks, migratory muscle pain, abdominal pain, a characteristic skin rash, and conjunctivitis or eye swelling are typical, often starting in childhood but sometimes in adulthood.

  • Is TRAPS dangerous?

    The main long-term risk is amyloidosis, a build-up of protein in organs such as the kidneys, caused by prolonged inflammation if the condition is untreated; with treatment, this risk is significantly reduced.

  • Is TRAPS genetic?

    Yes, it is an inherited autosomal dominant condition, meaning an affected parent has a 50% chance of passing the gene mutation to each child, and genetic testing can confirm the diagnosis.

  • Can TRAPS be cured?

    There is no cure, but biologic medications that block the underlying inflammatory pathway (such as IL-1 or TNF inhibitors) can control symptoms effectively and reduce the risk of long-term complications.

  • How is TRAPS treated?

    Treatment typically involves anti-inflammatory biologic drugs, particularly IL-1 blocking agents, alongside symptom management during flares with anti-inflammatory medication.

  • How long do TRAPS flares last?

    Individual episodes typically last one to three weeks, occurring every few weeks to months, though frequency and duration vary considerably between individuals.

  • TRAPS vs familial Mediterranean fever - what's the difference?

    Both are periodic fever syndromes, but TRAPS involves a TNF receptor gene mutation with longer-lasting episodes, while familial Mediterranean fever involves a different gene and typically causes shorter, more frequent episodes with a stronger link to certain ethnic backgrounds.

  • When should I see a specialist about recurrent fevers, and how quickly can I be seen privately?

    Recurrent unexplained fevers with the features above warrant referral to a rheumatologist or immunologist experienced in autoinflammatory disease. NHS waits can be lengthy; private specialists can often see you within about two weeks.