Persistent plaques and linear pigmentation in adult-onset Still's disease

A 25-year-old Japanese man presented with high spiking fever, arthralgia and a skin rash. A pruritic edematous erythema with persistent plaques was found mainly on the trunk; these lesions persisted even when the fever subsided, with prominent linear pigmentation. As marked neutrophilia and a high level of serum ferritin were detected, a diagnosis of adult-onset Still's disease (AOSD) was made, even though the persistent eruption was not characteristic of the disease. Oral prednisolone, together with low-dose methotrexate, was given with good results. In the literature, a similar atypical rash has been reported in 11 cases in Japan. All of them required high-dose administration of corticosteroids or other immunosuppressive agents. Severe systemic complications were seen in 3 patients, and 2 cases died of the disease. Persistent plaques and linear pigmentation are some of the manifestations of AOSD, which cannot be overlooked. This appearance could be an indication that suggests an increased risk of systemic complications and a prolonged time to clinical remission.