Unfolding dermatological spectrum of Still's disease: a cohort study from the International AIDA Network Still's Disease Registry

Objectives: To investigate cutaneous manifestations in Still's disease patients, evaluating any correlation with ethnic origin, age at disease onset, disease patterns, occurrence of macrophage activation syndrome (MAS) and systemic activity scores. Methods: Data were retrospectively drawn from the International AutoInflammatory Disease Alliance (AIDA) Network Registry dedicated to Still's disease. Results: A total of 518 patients (41.3% males) were enrolled. Salmon-coloured evanescent skin rash (n = 304, 63.9%), macules (n = 40, 7.7%), urticarial eruptions (n = 31, 5.9%), erythema (n = 27, 5.2%) and persistent pruritic papules and plaques (PPPP) (n = 25, 4.8%) accounted for the most frequent skin manifestations observed in Still's disease. Overall, atypical skin rash were described in 110 (21.2%) patients. Salmon-coloured evanescent skin rash and pruritus were more common among patients aged <16 years compared with patients aged 16-60 (P = 0.002 and P = 0.008, respectively). Pruritus was significantly more frequent among White than among Arab patients (P = 0.008) and in polycyclic vs monocyclic course (P = 0.049). Hispanics showed a significantly higher rate of atypical skin manifestations compared with Arabs (P = 0.036) and White (P = 0.036). Also, macules were more frequent among Hispanics than White (P = 0.027), while PPPP was more frequent among Hispanics than Arabs (P = 0.023) and White (P = 0.002). Salmon-coloured evanescent skin rash was significantly more frequent among patients with a systemic activity score ≥7 (P < 0.001). Conclusion: The present study enhances dermatologists' awareness of the diverse cutaneous lesions that may represent heterogeneous manifestations of Still's disease, shedding new light on the difference related to the age at disease onset, the patients' ethnic origin and the severity of the disease.