Pustular psoriasis in Malaysia: A review of the Malaysian Psoriasis Registry 2007–2018

Pustular psoriasis (PP) is an uncommon subtype of psoriasis with distinct genetic features and clinical phenotypes. Patients with PP tend to experience frequent flares and significant morbidity. This study aims to determine the clinical characteristics, co-morbidities and treatment of PP patients in Malaysia. This was a cross-sectional study of patients with PP notified to the Malaysian Psoriasis Registry (MPR) between January 2007 and December 2018. Of 21 735 psoriasis patients, 148 (0.7%) had pustular psoriasis. Of these, 93 (62.8%) were diagnosed with generalized pustular psoriasis (GPP) and 55 (37.2%) with localized PP (LPP). The mean age for pustular psoriasis onset was 31.71 ± 18.33 years with a male to female ratio of 1:2.1. Patients with PP were more likely to have dyslipidaemia (23.6% vs. 16.5%, p = 0.022), severe disease (Body surface area >10 and/or Dermatology Life Quality Index [DLQI] >10) (64.8% vs. 50%, p = 0.003) and require systemic therapy (51.4% vs. 13.9%, p < 0.001) compared to non-PP patients. Patients with PP also suffered greater impairment to their quality of life (DLQI >10, 48.9% vs. 40.3%, p = 0.046), had more days off school/work (2.06 ± 6.09 vs. 0.5 ± 4.91, p = 0.004) and a higher mean number of hospitalizations (0.31 ± 0.95 vs. 0.05 ± 1.22, p = 0.001) in 6 months compared to non-PP patients. Overall, 0.7% of psoriasis patients in the MPR had pustular psoriasis. Patients with PP had a higher rate of dyslipidaemia, severe disease, greater impairment of quality of life and systemic therapy usage compared to other psoriasis subtypes.