Clinical Features and Genetic Polymorphism in Chinese Patients with Erythrodermic Psoriasis in a Single Dermatologic Clinic.

BACKGROUND

Erythrodermic psoriasis (EP) is a rare variant of psoriasis that involves more complications and poorer biologic drug survival than plaque-type psoriasis vulgaris (PV). No prior study has explored human leukocyte antigen (HLA) or other genetic polymorphisms in patients with EP.

OBJECTIVES

Our objective was to describe the clinical features, comorbidities, and HLA polymorphisms among Chinese patients with EP.

METHODS

We enrolled consecutive patients with EP from our clinic, with EP defined as generalized confluent erythematous thin plaques covering at least 80% body surface area. Patients were categorized as having primary or secondary EP. Aggravating factors, comorbidities including psoriatic arthritis, family history of psoriasis, age of onset, and treatment history were also identified. Genetic studies were performed for HLA-C and HLA-DRB1, and the results were compared with those from a healthy population and patients with PV.

RESULTS

Of the 63 included patients, the male to female ratio was 2.71:1. Five (7.9%) patients had primary EP, and 58 (92.1%) had secondary EP. Genotyping of HLA-C and HLA-DRB1 was available in 61 and 58 subjects, respectively. HLA-C0102 was the most frequent HLA-C allele (34.4%), followed by HLA-C0702 (18.0%). The frequency of HLA-C0602 allele (4.1%) was lower than in patients with plaque-type psoriasis (4.1 vs. 16.3%, corrected p value [P] = 0.02) and similar to that in the healthy population in Taiwan. The most frequent HLA-DRB1 allele was HLA-DRB10901 (20.7%), followed by HLA-DRB1*0803 (13.8%). An increased prevalence of psoriatic arthritis (61.9%) and higher male predominance were also noted in comparison with PV.

CONCLUSIONS

There are HLA differences in Chinese patients with EP compared with patients with PV. The incidence of psoriatic arthritis is also higher. The implications of the above findings await further investigation.