Special area involvement, disease severity, and treatments in a real-world psoriasis population

Diagnosis of psoriasis is often based on clinical features, rather than histological examination. The use of tools such as body surface area (BSA), Physician’s Global Assessment, and the Psoriasis Area and Severity Index can help clinicians categorize the severity of psoriasis. However, these tools do not account for disease impact in special areas, such as the face, scalp, and genitals.

Here, we summarize a study by Horner et al.¹ in Dermatology and Therapy, which described BSA distribution, special area involvement, and available treatments, to evaluate disease burden in a real-world setting.

Study design and patient population¹

• This retrospective study evaluated 5,120 patients with a BSA measured between 2014–2020.
• Patients were aged ≥18 years, with at least one diagnosis of psoriasis within 90 days before and after the index date (the date of the first BSA value identified for the patient in the included data).
• BSA categories at baseline:

• • 23.4% of patients had a BSA of <3%
  • 41.9% of patients had a BSA of 3–10%
  • 34.6% of patients had a BSA of >10%

• Around half (49.3%) of patients were female, the majority were White (83.2%), and the most common comorbidities at baseline were hypertension (21.9%) and hyperlipidemia (17.8%).

Key findings¹

• In this real-world population, 77.3% had involvement in at least one special area (Figure 1A).
• Areas of involvement are shown in Figure 1B, the most common special area involved was the scalp (43.3%).
• The proportion of patients with involvement in two or more special areas was similar across the BSA categories.
• Of the 4,470 patients evaluated for initial treatment, majority received biologics (31.1%) or topicals (41.5%) only. 78.9% of patients received any topicals alongside other treatments.
• In patients with involvement of two or more special areas, the most common initial treatment was conventional synthetic anti-rheumatic drugs (54.1%), followed by topicals (48.3%), biologics (43.8%), and apremilast (43.5%).

*Adapted from Horner, et al.¹ 

Key learnings

Based on real-world data, most patients with special area involvement have a BSA of ≤10%. In patients with two or more special areas involved, approximately half were treated with topicals. These findings suggest that the International Psoriasis Council recommendations on use of systemics therapies are not reflected in the real-world, meaning patients who may benefit from systemic treatments are not being identified. Therefore, healthcare professionals should be aware of special areas and the associated recommendations when making prescribing decisions.