Flare Frequency and Duration in Patients with Generalized Pustular Psoriasis (GPP)

Abstract

Introduction: Generalized pustular psoriasis (GPP) is a rare, neutrophilic, chronic skin disease in which an overactivation of inflammatory pathways causes widespread erythema and eruption of sterile pustules that may coalesce into ‘lakes of pus’. GPP flares are heterogeneous, and there is no standard clinical definition. GPP flares are painful; severe cases may require emergency treatment and can lead to life-threatening complications such as sepsis. The objective of this study was to characterize the frequency, number, and duration of flares in patients with GPP.

Methods: We conducted a retrospective chart review including patients of all ages with a confirmed diagnosis of GPP after 2011 receiving care at 27 sites in France, Malaysia, and Tunisia.

 Results: Data from 175 patients were included (France: 58.9%, Malaysia: 31.4%, Tunisia: 9.7%). Mean (SD) follow-up was 5.0 (3.1) years. Flare-related care was the second most common reason for patient visits, accounting for 200 of 1378 follow-up visits after GPP diagnosis, surpassed only by routine follow-up. The mean (SD) annual number of flare episodes was 2.3 (2.0); the total number of flare episodes since the initial flare leading to diagnosis ranged from 0 to 9. Eighty-three (47.4%) patients experienced ≥1 flare episode after diagnosis, though individual country data suggested a higher flare burden in Tunisia (70.6%) and Malaysia (54.5%) versus France (39.8%). Twenty-eight patients (16.0%) had ≥2 flare episodes (60 visits); median (min, max) time between episodes was 11.6 (0.1, 52) months. The mean (SD) duration of flares was 34.3 (41.3) days during follow-up. Of 254 hospitalizations, 128 (50.4%) were flare-related inpatient admissions. Overall, 37.5% of GPP flares required inpatient care. The mean (SD) duration of flare-related admissions was almost twice as long as non-flare admissions at 19.2 (23.1) days versus 10.5 (8.1) days. Mean (SD) time between flare-related hospitalizations among 66 patients (128 hospitalizations) was 14.1 (17.1) months, with a median of 9.5 months indicating a skew distribution.

Conclusion: Flare episodes are a heavy burden for patients with GPP, with flares recurring as often as once a year and lasting up to 2 weeks or more. Flares account for >50% of hospitalizations for patients with GPP and are an important cause of follow-up care visits. The frequency of flares varied between patients, with some individuals experiencing up to 10 episodes over the study period. Heterogeneity of flares and rarity of GPP make diagnosis and clinical study challenging, while the severity of acute episodes and the burden of flare reoccurrence demonstrate the need for more effective treatment options.