Oxidative Stress and Generalised Pustular Psoriasis: Report of d‐<scp>ROM</scp> Measurements in Nine Cases Including Three of Pustular Psoriasis of Pregnancy

Reactive oxygen species (ROS) are involved in the pathogenesis of generalised pustular psoriasis (GPP), but this involvement has not been fully elucidated. We performed the diacron-reactive oxygen metabolite (d-ROM) test and the biological antioxidant potential (BAP) test on sera from nine patients with active GPP who were hospitalised and treated at our hospital, including three patients with pustular psoriasis of pregnancy (PPP). The serum d-ROM and BAP levels were evaluated before treatment and at 1 month of treatment. We also performed immunostaining of 4-hydroxy-2-nonenal (4-HNE) in skin tissues. In the GPP patients, the average d-ROM levels were significantly reduced at 1 month of treatment (reduced to 343.0 ± 82.1 U.Carr from 423.2 ± 95.0 U.Carr, p = 0.005). The Generalised Pustular Psoriasis Area and Severity Index (GPPASI) score correlated with d-ROM levels (r = 0.57, p = 0.10), suggesting that those levels reflect the disease severity. In normal pregnancy, d-ROM values are known to increase from mid-term to late-term. The d-ROM values increased when GPP worsened in the case of PPP. Immunohistochemical staining of 4-HNE was positive for subcorneal pustules, neutrophils, and for the cytoplasm of epidermal keratinocytes, especially in upper epidermal layers. Our findings indicate that 4-HNE may play an important role in GPP and PPP.