Navigating the Misdiagnosis of Pityriasis Rubra Pilaris and Successful Treatment With Guselkumab - A Case Report of Dual Biologic Therapy

Sep 28, 2026

Uploaded by dabgoudw

Pityriasis rubra pilaris (PRP) is a rare chronic dermatologic condition frequently mistaken for psoriasis, leading to major quality-of-life impairment from discomfort and systemic symptoms. Standard options such as retinoids, corticosteroids, and methotrexate can be ineffective, especially in refractory disease. This open-access case report details successful management of PRP with guselkumab after diagnostic confirmation by punch biopsies and failed conventional therapies, including sustained clearance at one year.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages3

Reading Time8 min

AccessFree to download

Abstract

Introduction

Case Presentation

Review began 11/06/2025 Review ended 11/24/2025 Published 12/01/2025 © Copyright 2025 Bongfeldt et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CCBY 4.0. , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited. DOI: 10.7759/cureus.98267 Open Access Case Report Navigating the Misdiagnosis of Pityriasis Rubra Pilaris and Successful Treatment With Guselkumab: A Case Report of Dual Biologic Therapy Danika Bongfeldt 1, Sylvia Martinez-Cabriales 1 1. Dermatology, Northern Ontario School of Medicine (NOSM) University, Sudbury, CAN Corresponding author: Danika Bongfeldt, [dbongfeldt@nosm.ca](dbongfeldt@nosm.ca) Abstract Pityriasis rubra pilaris (PRP) is a rare and chronic dermatologic condition often misdiagnosed due to its clinical resemblance to psoriasis. It significantly impacts quality of life due to its clinical presentation and systemic discomfort. Conventional treatments, including retinoids, corticosteroids, and methotrexate, often yield suboptimal outcomes, particularly in refractory cases. Recently, biologic therapies have shown promise for PRP management. This case report describes the successful treatment of PRP with guselkumab. A 57-year-old male presented with an eight-year history of refractory papulosquamous disorder affecting 70% of his body surface area, initially diagnosed and treated as psoriasis. The patient had failed topical steroids, topical calcineurin inhibitors, sulfasalazine, and methotrexate. He had a past medical history of asthma treated with dupilumab. On skin exam, there were orange-red scaly plaques on the scalp, trunk, upper and lower extremities, buttocks, and genitals. Some of the plaques coalesced in areas to confluence, making PRP a presumptive diagnosis. Diagnosis was confirmed by three punch biopsies, and treatment with guselkumab 100mg subcutaneous injection was initiated. The patient noted improvement after the first loading dose and achieved complete skin clearance following the second dose four weeks later. At his oneyear follow-up, he maintained full clearance while receiving guselkumab 100 mg subcutaneously every eight weeks. This case highlights the potential of guselkumab as an effective treatment for refractory PRP, even in cases of extensive disease. It underscores the importance of accurate diagnosis through biopsy and demonstrates the feasibility of concurrent biologic therapies for managing comorbid inflammatory conditions. Further research is needed to optimize biologic treatment strategies and enhance understanding of dual biologic use in complex dermatologic cases. Categories: Dermatology Keywords: dual biologic therapy, dupilumab, guselkumab, pityriasis rubra pilaris, psoriasis Introduction Pityriasis rubra pilaris (PRP) is a rare, chronic skin disorder that is commonly misdiagnosed due to its rarity and resemblance to other skin conditions [1,2] . PRP has a profound impact on an individual’s quality of life, with symptoms including discomfort, poor sleep, itching, anhidrosis, body temperature dysregulation, and self-consciousness [3] . Its therapeutic guidelines are limited: current conventional treatments include retinoids, phototherapy, corticosteroids, and methotrexate [1] . Recently, off-label biologic therapies have been effective in managing PRP; however, this data is limited to mostly case reports and case series [1,4,5]. Therefore, the goal of this case report is to contribute more data regarding the off-label use of biologics in managing PRP. This article was previously presented as a meeting abstract at the 2025 100th Canadian Dermatology Association Annual Conference on June 18, 2025. Case Presentation A 57-year-old male presented for assessment of severe psoriasis diagnosed eight years ago. The onset of his lesions started 20 years ago. He had failed topical steroids, sulfasalazine

FAQs

Why was the patient initially misdiagnosed, and how was PRP confirmed?

The condition resembled psoriasis and was initially diagnosed as psoriasis. PRP was confirmed using three punch biopsies after clinical features suggested PRP rather than psoriasis.

What treatments were tried before guselkumab, and what failures were reported?

Topical steroids, topical calcineurin inhibitors, sulfasalazine, and methotrexate were unsuccessful. The patient also had refractory papulosquamous disease over many years despite these conventional approaches.

How effective was guselkumab, and how durable was the response?

The patient improved after the first loading dose and achieved complete skin clearance after the second dose four weeks later. At the one-year follow-up, full clearance was maintained with ongoing guselkumab every eight weeks.

Sep 28, 2026

Uploaded by dabgoudw