Diagnosis and Assessment of Psoriasis for the Rheumatologist: A Workshop From the GRAPPA 2024 Annual Meeting

Rheumatologists and other nondermatologists often encounter patients with psoriatic arthritis (PsA) who present with cutaneous diseases that mimic psoriasis (PsO). Cutaneous disorders including tinea, seborrheic dermatitis, eczema, pityriasis rubra pilaris, syphilis, or cutaneous lymphoma are commonly mistaken for PsO. It is crucial for rheumatologists and other nondermatologists to recognize alternative conditions and to consider referral to dermatology when skin disease is not responding to therapy. Correct diagnosis is important when assessing disease severity in clinical practice as well. Although the Psoriasis Area and Severity Index (PASI) and the Dermatology Life Quality Index (DLQI) are gold standards for physician- and patient-reported outcomes in clinical trials, they are not practical to deploy in busy clinical practice. Use of a physician global assessment (PGA), body surface area using a handprint method, and informal patient-reported outcomes can be useful in documenting the burden of disease. A treat-to-target approach using a PGA of clear/almost clear is ideal. At the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2024 annual meeting, a 2-part workshop was conducted for rheumatologists to first review skin disorders commonly mistaken for PsO, and second, to review outcome measures best suited for clinical practice.