Clinical and histopathological features of cutaneous manifestations of adult-onset Still disease.

Adult-onset Still disease (AOSD) is a rare autoinflammatory syndrome characterized by recurring fevers, arthralgia, and consistent laboratory abnormalities that include leukocytosis and hyperferritinemia. Skin findings accompany the disease in nearly 90% of the cases. Early reports described evanescent, pruritic, salmon-pink or urticarial lesions, referred to as the typical eruption of AOSD. Histopathologic findings consist of superficial perivascular dermatitis with varying number of interstitial neutrophils. Later reports described a more persistent rash that tended to be photodistributed, hyperpigmented, often in a linear configuration, sometimes in a rippled pattern, referred to as the atypical eruption of AOSD. The presence of individual necrotic keratinocytes in the upper spinous layer has been the consistent histopathologic finding. The persistent rash may not represent an atypical presentation of AOSD as recent reports indicate a high prevalence of the rash. Emerging data also suggest that patients with persistent eruption have a worse prognosis. The recognition of the clinical and histopathological findings of skin eruptions of AOSD may facilitate an earlier diagnosis, potentially improving disease outcome. Herein, clinical and histopathological features of cutaneous manifestation of AOSD in 2 Asian women are highlighted accompanied by a relevant review of the disease.