Persistent pruritic papules and plaques associated with adult-onset Still's disease: report of six cases.

Typical skin rash, which appears and disappears along with respective rise and fall of fever, is well-known, and included as one of the major criteria of adult-onset Still's disease (AOSD) (Yamaguchi's criteria). In addition, various skin lesions are occasionally observed in association with AOSD. Persistent pruritic eruptions present with some clinical features, such as urticarial erythema, flagellate erythema, erythematous, slightly scaly or crusted papules, and/or plaques on the trunk and extremities. These lesions show unique histological features such as dyskeratosis with a peculiar, distinctive distribution in the upper epidermis and cornified layers with focal hyperkeratosis. We describe herein six cases of AOSD, which presented with skin lesions of persistent pruritic papules and plaques. All six cases were female, and three of them were elderly women. The patients presented with linear erythematous streaks, scaly erythema, keratotic papules, infiltrative plaques and irregular coalesced erythemas. By contrast, histological features were characteristic, and dyskeratotic cells were found in the horny layers as well as in the upper layers of the epidermis. Persistent pruritic eruption is an important cutaneous sign for the diagnosis of AOSD.