For patients with psoriasis vulgaris (PsV), comorbidities such as psoriatic arthritis (PsA), tonsillitis and sinusitis are associated with a diagnosis of generalized pustular psoriasis (GPP), according to new findings The most likely associated comorbidities are treated with: systemic corticosteroids and phototherapy.1
These findings come from a retrospective cohort study conducted using data extracted from Japanese health insurance claims and aimed to highlight factors associated with GPP diagnosis in patients with PsV.
The study’s researchers note that while it is clear that patients with GPP often have comorbidities or symptoms, it remains less clear whether comorbidities or symptoms in patients with PsV are associated with an increased risk of developing GPP.2 To address this issue, the new study was conducted and led by Dr. Koremasa Hayama of Nihon University School of Medicine in Tokyo, Japan.
“PsV is dominated by the adaptive immune response (Th17 pathway), whereas GPP is dominated by the innate immune response (interleukin (IL)-36 pathway); therefore, it is unclear why some patients with PsV continue to receive a GPP diagnosis,” write Hayama and colleagues.
The researchers used a retrospective cohort study design, with patient claims data obtained from the Japan Medical Data Center (JMDC). It is understood that JMDC covers more than 4 million people employed in Japan.
The team’s study ran from July 2005 to January 2019 and consisted of two distinct cohorts: the first consisted of individuals diagnosed with PsV only (referred to as the PsV-only group), and the second cohort consisted of individuals diagnosed with PsV only. Constituting the group subsequently diagnosed with GPP—PsV with GPP.
The “PsV only” group included patients with 2 confirmed PsV diagnoses during the study period, and the “PsV with GPP” group included patients with 2 confirmed PsV diagnoses in addition to 1 confirmed GPP diagnosis. The same time frame as the PsV-only group.
Patients included in both study arms maintained ongoing insurance enrollment after the second PsV claim, and investigators determined the index date as the date of the second PsV diagnosis code.
The research team’s follow-up period will end at the earliest of the following: for PsV in the GPP group, continuous enrollment or the end of the maximum follow-up time; for the PsV group with GPP, this period ends when the patient is first diagnosed with GPP.
Overall, the researchers found that the most significant factor associated with a GPP diagnosis was PsA (OR 20.2, 95% CI 17.06–23.92, ask< 0.0001). They added that the median time from event to diagnosis of psoriatic arthritis was 119 days.
The team also found that other comorbidities, such as tonsillitis, other types of psoriasis, and sinusitis, were also associated with GPP. In terms of associated treatments, systemic corticosteroids (OR 2.19, 95% CI 1.98–2.43, ask< 0.0001) was found to be associated with GPP, and the team noted that the median time from the start of treatment to the diagnosis of GPP was 180 days.
In contrast, however, studies have reported that other treatments, including interleukin (IL)-17 or IL-23 inhibitors, immunosuppressants, and phototherapy, delayed patient GPP by ≥1 year from treatment initiation to diagnosis. They also found that symptoms such as headache, back pain and fever proved to be indicators of a possible future diagnosis of GPP.
Overall, the researchers found that individuals with PsV who also required systemic therapy were more likely to receive a GPP diagnosis than those who did not, providing useful insights for clinicians to identify high-risk PsV patients and support early treatment. Diagnose the patient’s GPP.
“By increasing awareness of GPP among physicians treating patients with moderate to severe PsV, these findings may support physicians in identifying patients potentially at high risk for GPP and facilitate early diagnosis,” they wrote. “Further research is needed to determine the clinical context of GPP diagnosis in patients with PsV. Course and pathology.”
- Hayama, K, Iwasaki, R, Tian, Y, Fujita, H. Factors associated with progression of generalized pustular psoriasis in Japanese patients with psoriasis vulgaris: results from a claims database study. J. DeMattol. 2023;00:1–8. https://doi.org/10.1111/1346-8138.16949.
- Ohata C, Tsuruta N, Yonekura K, Higashi Y, Saito K, Katayama E, et al. Clinical features of pustular psoriasis in Japan: a multicenter observational study. J. DeMattol. 2022;49:142-150.