An atypical persistent eruption of adult-onset Still's disease with neutrophilic urticarial dermatosis-like dermal features: A case report and review of the literature

New insights on multigenic autoinflammatory diseases

Autoinflammatory diseases are disorders of the innate immune system, which can be either monogenic due to a specific genetic mutation or complex multigenic due to the involvement of multiple genes. The aim of this review is to explore and summarize the recent advances in pathogenesis, diagnosis, and management of genetically complex autoinflammatory diseases, such as Schnitzler's syndrome; adult-onset Still's disease; synovitis, acne, pustulosis, hyperostosis, osteitis syndrome/chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis; Adamantiades-Behçet's disease; Yao syndrome; and periodic fever with aphthous stomatitis, pharyngitis, and adenitis syndrome. The PubMed database was screened for relevant articles using free text words and specific search strings. The search was limited to English-language articles, reporting the results of studies in humans, published through March 2021. Evidence from literature suggest that these rare multigenic autoinflammatory diseases can present with different clinical features and the diagnosis of these diseases can be challenging due to a combination of nonspecific manifestations that can be seen in a variety of other conditions. Diagnostic delays and disease complications may occur due to low disease awareness and the lack of pathognomonic markers. The pathogeneses of these diseases are complex and in some cases precise pathogenesis is not clearly understood. Conventional treatments are commonly used for the management of these conditions, but biologics have shown promising results. Biologics targeting proinflammatory cytokines including IL-1, IL-6, TNF-α, IL-17A and IL-18 have been shown to ameliorate signs and symptoms of different multigenic autoinflammatory diseases.

Successful treatment of secondary macrophage activation syndrome with emapalumab in a patient with newly diagnosed adult-onset Still's disease: case report and review of the literature

Here, we present a 22-year-old female patient with adult-onset Still's disease (AOSD) who was newly diagnosed in the setting of secondary macrophage activation syndrome (MAS), a rare, life-threatening inflammatory disease with 50% mortality due to multi-organ failure. She met the diagnostic criteria of AOSD and MAS, while genetic testing excluded primary causes of MAS. She had high fevers, anemia, thrombocytopenia, splenomegaly, hematophagocytosis, and elevated serum ferritin (37,950 ng/mL) and CD25 levels (11,870 pg/mL), which remained unresponsive to corticosteroids and anakinra. Her serum interferon gamma (IFN-γ) levels were elevated (7 pg/mL). She was markedly responsive to IFN-γ blockade with emapalumab that eliminated her fevers and all MAS-associated laboratory abnormalities. This report provides initial evidence for therapeutic efficacy for IFN-γ blockade in AOSD and secondary MAS.

Adult-onset Still's disease as a cutaneous marker of systemic disease

Adult-onset Still's disease (AOSD) is a rare, systemic, inflammatory disorder characterized by spiking fevers, an evanescent eruption, arthritis, and multiorgan involvement. The disease has been recently classified as a polygenic autoinflammatory disorder at the "crossroads" of autoinflammatory and autoimmune diseases. The highly characteristic salmon-colored eruption is a cutaneous manifestation of a generalized inflammatory reaction and an important diagnostic criterion. In addition to the evanescent eruption, there are atypical persistent papules and plaques in many patients with AOSD. Emerging data suggest that AOSD with this typical evanescent eruption has a different clinicopathologic presentation and clinical course than AODS with atypical cutaneous manifestations. It appears that there are two subtypes of AOSD with different immunologic profiles, including (1) a systemic disease with high fever, organ involvement, and elevated levels of ferritin, and (2) a chronic disease course with arthritis as the predominant finding. These observations provide novel insight into the disease pathogenesis, suggesting that the underlying mechanisms might differ between these two forms, partially explaining the reported differences in drug response. Recent advances in the understanding of AOSD are summarized with a focus on the spectrum of cutaneous manifestations and its relationship to systemic inflammation.