Prurigo pigmentosa as an atypical persistent plaque-like skin rash in adult-onset Still's disease: case report and literature review. (October 2013) - Muthalaly, Asha S
Adult-onset Still's disease (AOSD) is a systemic inflammatory disease of unclear etiology. It is classically characterized by spiking fevers, arthralgias, leukocytosis and a typical rash. Usually most of these clinical findings are not specific to this disease and it is often a diagnosis of exclusion. The exception to this is usually the typical maculopapular nonpruritic salmon-colored eruption, which has been shown to have high sensitivity and specificity for the diagnosis of patients with AOSD. It is important to be aware, however, that some patients also present with an atypical rash. Prurigo pigmentosa is a distinctive inflammatory disease first described in Japan. The patient in our case presentation was diagnosed with AOSD based on Yamaguchi criteria and also had a diffuse pruritic persistent hyperpigmented rash on the back, chest and distal extremities with a biopsy revealing histopathology and clinical findings consistent with the diagnosis of prurigo pigmentosa. This review of literature was carried out to examine all the known cases of persistent plaques associated with AOSD. The findings indicated that the histopathologic and clinical findings were similar to those found in prurigo pigmentosa. AOSD can be a chronic debilitating disease if left untreated and can ultimately lead to death. Prurigo pigmentosa may be an under-recognized atypical skin manifestation of AOSD that rheumatologists need to consider in clinical practice.