The autoinflammatory syndromes are a rare group of diseases for which the specific causes have been determined. The diseases in this category include hyper-immunoglobulin D (hyper-IgD) syndrome (HIDS), the cryopyrinopathies, familial Mediterranean fever (FMF), and tumor necrosis factor (TNF) receptor associated periodic syndrome (TRAPS). The cryopyrinopathies are a group of conditions made up of Muckle-Wells syndrome, familial cold autoinflammatory syndrome (FCAS), neonatal-onset multisystem inflammatory disease (NOMID), and chronic infantile neurological cutaneous and articular syndrome (CINCA). These groupings were first proposed in the 1990s to bring together a collection of inflammatory disorders that are distinct in nature and pathophysiology from other forms of allergic, autoimmune, and immunodeficiency syndromes. Patients with these auto-inflammatory diseases lack the autoreactive immune cells (T and B cells) as well as autoantibodies. The identification of specific genes that are defective and the roles played by those genes in the development of these disorders has been critical in increasing understanding of these diverse diseases. The common link in these conditions is the fact that they all represent abnormalities of the innate immune system.
|PATHOPHYSIOLOGY OF AUTOINFLAMMATORY SYNDROMES|
Clinical Findings: HIDS is inherited in an autosomal recessive fashion. Patients present with fever, arthralgias, abdominal pain, cervical adenopathy, and aphthous ulcers. Skin findings are consistent with a cutaneous vasculitis with palpable purpura and purpuric macules and nodules. Patients develop attacks of these symptoms with some evidence of periodicity. The attacks can last from 3 to 7 days, and typically the first attack occurs within the first year of life. As the child ages, the frequency and the severity of the attacks lessen. No reliable trigger has been found that initiates the attacks, and patients are completely normal between attack episodes.