Interconnections of Psoriasis in Special Body Areas

Image Credit: © ksu_ok - stock.adobe.com

Although there is a wealth of information on general psoriasis, there remains a gap in research into the unique characteristics of psoriasis in special body areas. A recent study used data from the Chinese Psoriasis Standardized Diagnosis and Treatment Center to perform statistical analyses on the demographic and clinical characteristics of patients with psoriasis in special body areas, as well as explore the relationships between different affected areas.¹

The researchers behind the study aimed to better understand the treatment needs of these patients and provide clinical research evidence for treatment decision-making. They found that the prevalence of psoriasis in these special body areas increased with escalating psoriasis severity, and those with genital involvement are more likely to have other special body area involvements.

Methods

The data for this study was taken from the Psoriasis Standardized Diagnosis and Treatment Center, which, as of March 2022, encompassed 402 hospitals, with over 500,000 cumulative enrolled cases nationwide. Patients diagnosed by dermatologists in collaborating hospitals between January 2020 and September 2021 were included if they exhibited involvement in the scalp, palmoplantar, genital, or nail areas.

Participating dermatologists collected enrollment data through questionnaires. This included demographics, Investigator’s Global Assessment (IGA), percentage of affected body surface area (BSA), Psoriasis Area and Severity Index (PASI), comorbidity history, and Dermatology Life Quality Index (DLQI).

Results

Upon review of the Psoriasis Standardized Diagnosis and Treatment Center, researchers identified 346 patients with plaque psoriasis involving at least 1 of the following: the scalp, palmoplantar, genitals, or nails. The study identified that most patients (81.6%) had 2 or more special areas affected. Researchers stated that a high percentage of patients with nail psoriasis also had concomitant scalp psoriasis (75.4%) and palmoplantar (34.9%) psoriasis.

The study reported that patient characteristics were generally similar regardless of involvement of psoriasis in special body areas. Researchers found the only notable differences to be that patients with scalp psoriasis were typically younger, and palmoplantar psoriasis was associated with the highest percentage of former or current smokers (39%). They stated that the most common comorbidity was cardiovascular disease (12.4%) and only 18.8% of patients had a positive family history of psoriasis.

Most patients included in the study had moderate to severe disease, with 61.4% having an IGA ≥ 3, 84.3% having BSA ≥ 3%, and 45.9% having a PASI score > 10. Researchers found the DLQI score revealed a median score of 9.0 (11.0), with 68.1% of patients reporting a moderate or greater impact on life. Genital psoriasis showed the highest median BSA involvement (23.0) and PASI score (14.3), with the same trend in DLQI (12.0).

Researchers discovered that the prevalence of psoriasis in the nails, scalp, palmoplantar, and genitals increased with escalating psoriasis severity. The study reported that 81% of all patients had at least 2 specific body regions involved, which increased as the severity of the disease worsened.

The study stated that the factors associated with the occurrence of special areas of psoriasis are currently unknown. Researchers reported that patients with genital psoriasis had an eightfold increased risk of having scalp involvement and palmoplantar involvement compared to those without genital psoriasis.

Treatment Plans

According to this initial treatment identified in the registry (patients could have multiple initial treatments), researchers stated more than half of the patients were treated with topicals (68.8%), traditional medications (39.8%), and the highest proportion (27.5%) of patients with palmoplantar were treated with biologics. When compared to patients with psoriasis at a single area, the study found an increase in the proportion of patients with psoriasis involving two or more special areas receiving biologics and a decrease in traditional therapy and topicals alone.

Conclusion

This study observed interconnections between special areas, particularly with patients having genital psoriasis exhibiting a higher likelihood of concurrent scalp and palmoplantar psoriasis. Although previous data on the effectiveness of psoriasis in special areas was limited, the study found asignificant escalation in the proportion of biologics when the involvement of special areas was ≥ 2. Nails were identified as the most common area, contrasting with scalp predominance in other research.² Researchers suggested more studies with larger sample sizes are needed to draw definitive conclusions on treatment options for patients with area-special psoriasis.

References

1. Gao Y, Li C, Tong M, et al. Characterization of psoriasis patients in special body areas: real-world evidence from the chinese psoriasis standardized diagnosis and treatment center. J Dermatolog Treat. 2024;35(1):2337264. doi:10.1080/09546634.2024.2337264
2. Egeberg A, See K, Garrelts A, et al. Epidemiology of psoriasis in hard-to-treat body locations: data from the Danish skin cohort. BMC Dermatol. 2020;20(1):3. Published 2020 May 20. doi:10.1186/s12895-020-00099-7