▸ Tumor Necrosis Factor-Receptor Associated Periodic Syndrome (TRAPS). Children with TRAPS may have a lifelong history of febrile episodes that last 2-3 weeks at a time, but the febrile episodes only occur 2-3 times per year.
Conjunctivitis and raised red lesions distinguish TRAPS from other familial periodic fever syndromes. One study of 25 TRAPS patients showed that 21 (84%) had erythematous patches, including both wavy and circular lesions (N. Engl. J. Med. 2001;345:1748-57). Other clinical features of TRAPS include myalgia, arthralgia, and abdominal pain.
Skin manifestations are much more common with TRAPS than with the other familial periodic fever syndromes. "Almost all of these children will have skin lesions that may persist even when the fever is gone," Dr. Edwards noted.
When a febrile episode occurs, TNF receptors are suppressed, which creates an uncontrolled inflammatory response. Consequently, TNF inhibitors can be used to treat these patients, Dr. Edwards said.
▸ Muckle-Wells Syndrome/Familial Cold Urticaria. These two syndromes are both associated with mutations of the CIAS1 gene family. Mutations in these genes lead to autoinflammatory syndromes in which large numbers of cytokines are generated, which means that amyloidosis is very frequent in these individuals.
Patients with Muckle-Wells syndrome (MWS) generally present with urticaria and progressive sensorineural loss and deafness. Because MWS is a disease of dominant genes, the parent may show signs of hearing problems, which should prompt clinicians to include MWS in the differential diagnosis of recurrent urticaria and fever.
By contrast, patients with familial cold urticaria will present not only with urticaria and wheals, but with complaints of painful joints, chills, and fever. Febrile episodes in patients with familial cold urticaria generally occur several hours after exposure to cold. Both syndromes are associated with German, English, French, and North American ancestry.