Case report: Area of focus of management of severe pityriasis rubra pilaris by dose optimization of adalimumab biosimilar in combination with acitretin and montelukast

Abstract

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disorder characterized by hyperkeratotic follicular papules, orange-red scaling plaques with islands of sparing and palmoplantar keratoderma. While spontaneous resolution occurs in some cases, treatment can be challenging for others. The use of biologics in PRP management has gained attention in recent studies, although their high costs and potential side effects present limitations. We present a case of a 71-year-old patient with treatment-resistant PRP who showed significant improvement through optimized adalimumab treatment. Considering the emerging role of phospholipase A2 in PRP pathogenesis, montelukast was added, further enhancing the therapeutic response. By maintaining montelukast and prolonging the adalimumab interval to 3 and 4 weeks, effective dose optimization was achieved without PRP relapse. This case report highlights the potential for adalimumab dose optimization by shortening the initial treatment interval for increased effectiveness and lengthening the interval during the maintenance phase to conserve medication doses. Montelukast appears to assist in sustaining clinical outcomes during interval prolongation, necessitating further investigation through additional studies.

Keywords: adalimumab; biosimilar; dose-optimization; montelukast; phospholipase A2; pityriasis rubra pilaris.