Clinical Description
To date, more than 200 individuals have been identified with a pathogenic variant in TNFRSF1A [Cudrici et al 2020]. As a periodic fever syndrome, TNF receptor-associated periodic fever syndrome (TRAPS) is characterized by episodes of inflammation typically occurring every four to six weeks and lasting between five and 25 days. Flares may be prompted by stress, infection, trauma, hormonal changes, and vaccination. Symptoms may include fever, abdominal pain, arthralgia, myalgia, migratory rash, and eye inflammation, with variable severity. Symptoms often begin in early childhood (median age 4.3 years), though symptom onset can occur later in life, especially in those with mild or somatic pathogenic variants (see Molecular Genetics). During a flare, acute-phase reactants such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and serum amyloid A are typically elevated. Generally, acute-phase reactants stabilize between flares but may remain somewhat elevated even in the absence of clinical symptoms. Symptom severity does not appear to correlate with sex.
Table 2.
TNF Receptor-Associated Periodic Fever Syndrome: Frequency of Select Features
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Feature | % of Persons w/Feature | Comment |
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Fever | 96% | Periodic in nature & generally longer in duration than in persons w/other periodic fever syndromes |
Abdominal pain | 70% | |
Arthralgia | 69% | |
Myalgia | 69% | |
Maculopapular/ migratory rash | 60% | |
Conjunctivitis | 37% | |
Periorbital edema | 28% | |
Chest pain | 33% | |
Fever occurs in the majority (~96%) of individuals with TRAPS at some point in time. Febrile episodes typically occur every four to six weeks, and these flares are typically much longer in duration than in individuals with other hereditary periodic fever syndromes [Cudrici et al 2020].
Pain in individuals with TRAPS is typically caused by inflammation in the surrounding tissues. It can affect the abdomen, bones and joints, chest, muscles, scrotum, and eye. Pain may migrate with rashes throughout a flare and often affects the same areas of the body. Abdominal pain during flares is noted in most (~70%) individuals with TRAPS; however, it is not always accompanied by other gastrointestinal symptoms such as nausea or diarrhea.
Gastrointestinal (GI) findings affect around 70% of individuals with TRAPS during flares. They generally consist of broad pain as a result of serositis, but symptoms like diarrhea, constipation, vomiting, aseptic peritonitis, and GI bleeding can occur. In some cases, splenomegaly and/or hepatomegaly may be noted outside of a flare, especially in cases of untreated AA amyloidosis.
Ophthalmologic findings including conjunctivitis and periorbital edema during a flare are seen in about 50% of affected individuals. Periorbital edema, in the context of other symptoms, appears to be a distinguishing feature of TRAPS compared to other periodic fever syndromes. Ocular findings are caused by inflammation in and around the eye and generally resolve with treatment [Lachmann et al 2014, Maccora et al 2021].
Skin/mucocutaneous findings are common features and often migrate with myalgias in the arms and legs throughout the course of a flare. Inflammation of the fascia of a muscle (fasciitis) has been also reported. Histologically, skin lesions often contain nonspecific perivascular infiltrates of lymphocytes and monocytes. Types of skin findings include the following:
Maculopapular/migratory rashes consisting of both flat and raised lesions on the skin. In individuals with TRAPS, the rash frequently migrates distally down the limbs as a flare progresses. This rash is typically not itchy.
Urticarial rashes (also known as hives) that are raised and often itchy.
Erysipelas-like erythema consisting of raised rashes typically affecting the lower limbs. Such rashes may be warm to the touch and can be quite tender.
Mucocutaneous findings such as pharyngitis and aphthous stomatitis have been reported in a number of individuals with TRAPS [Cudrici et al 2020].
AA amyloidosis is the most severe sequela of TRAPS but can largely be avoided with adequate treatment (see Management). AA amyloid is produced during acute-phase reaction, and development of amyloidosis has been associated with a number of inflammatory conditions including other autoinflammatory diseases. Amyloid buildup is caused by misfolding of the serum amyloid A protein during periods of inflammation. This misfolded protein is unable to be cleaved and excreted, and it deposits in the organs. Proteinuria and kidney failure occur in 80%-90% of affected individuals with amyloidosis, while intestinal, thyroid, myocardium, liver, and spleen deposits are less common.
Lymphadenopathy is present in about 15% of individuals with TRAPS and can include enlarged cervical lymph nodes (often painless) as well as generalized lymphadenopathy.
Cardiac findings. Inflammation of the pericardium may lead to pericarditis and chest pain. This finding is present in about 30% of individuals with TRAPS.
Respiratory findings are generally rare, but around 2% of affected individuals report persistent cough and 1% report recurrent pneumonia. The link between respiratory findings and TRAPS remains unclear.
Neurologic findings in individuals with TRAPS are rare, but headaches and seizures have been reported in some affected individuals [Cudrici et al 2020].