The presentation of generalized pustular psoriasis (GPP) is generally heterogeneous, according to a study published in Experimental Dermatology. 

Although GPP is best known for its recurrent flares of sterile pustules, various systemic complications and comorbidities may also be present. This creates a diagnostic challenge for physicians and can cause significant distress among patients. 

Existing studies point to the heterogeneity of symptoms based on age, medical history, as well as the frequency/severity of flares or systemic inflammation. The authors of the study sought to better characterize the heterogeneity of GPP to aid in the development of more individualized therapeutics. 

The research team obtained all GPP and psoriasis vulgaris (GPP is sometimes classified as a severe variant of this condition) cases from their hospital between January 1, 2010, and November 30, 2022. They then compared the clinical difference between patients with GPP and matched psoriasis vulgaris; patients with lesions typical of psoriasis vulgaris 6 months prior to GPP diagnosis were classified as having GPP with psoriasis vulgaris, otherwise they were classified as having GPP alone. 

Read more about GPP etiology

“Given that the assessment of generalized pustular psoriasis area and severity index (GPPASI) is a subjective process, we have implemented measures to ensure objectivity and credibility throughout the assessment process,” the authors wrote. 

Among these measures was assessing GPPASI based on criteria from previous trials. They also made use of the intraclass correlation coefficient to reduce the possibility of observer bias. 

Four hundred sixteen patients were eligible for this study. The research group also identified 416 patients hospitalized for psoriasis vulgaris during the same study period for comparison. The research team found GPP to be a clinically heterogenous disease, both in patients with or without psoriasis vulgaris. Heterogeneity in clinical presentation could be observed depending on factors such as age group. In addition, the presentation of patients with GPP, both with or without psoriasis vulgaris, differed in terms of comorbidities and inflammation-related indicators present. 

“More attention on the heterogeneity of this severe disease is warranted to meet the unmet needs and promote the individualized management of GPP,” the authors concluded. 


Xu Z, Liu Y, Qu H, et al. Clinical characteristics and heterogeneity of generalized pustular psoriasis: a comparative study in a large retrospective cohortExp Dermatol. Published online July 26, 2023. doi:10.1111/exd.14891