The Role of IL-17 in Papulopustular Rosacea and Future Directions

Abstract

Rosacea is a chronic, progressive, inflammatory condition phenotypically subtyped into diagnostic features, major features, and minor/secondary features. There is currently no cure for rosacea, and it carries a significant negative psychosocial burden for afflicted patients. While there are a number of treatment modalities at the disposal of the clinician, clinical experience has suggested a need for updated treatments. The pathogenesis of rosacea is multifactorial; however, this paper will focus on the pivotal role of interleukin 17 (IL-17) in the development and progression of the disease. Furthermore, this paper will explore the mechanism of action of standard rosacea treatments and their effect on different stages of the IL-17 pathway. The standard treatments for rosacea are usually effective in controlling the symptoms of the disease in its mild-to-moderate form; however, their efficacy is diminished in the setting of severe and treatment-resistant rosacea. We hypothesize that IL-17 inhibitors, currently used successfully in psoriasis and psoriatic arthritis, could perhaps be used to treat severe and treatment-resistant papulopustular rosacea in the future; however, clinical trials and case reports will be needed to dictate expanded indications of IL-17 inhibitors. Furthermore, the high cost of IL-17 inhibitors presently prevents their use in disease states other than psoriasis or psoriatic arthritis.

Ocular manifestations of rosacea: A clinical review

“…Given its chronic inflammatory nature, novel, future approaches targeting the causative inflammatory mediators involved in the pathophysiology of rosacea may become available in the future to help prevent the progression of the condition. Such approaches may include, targeting the pro‐inflammatory interleukins, IL‐17 122 and toll‐like receptors 79 …”

The Theranostics Role of Mast Cells in the Pathophysiology of Rosacea

“…Th1 cells along with Th17 cells, differentiated from CD4 + T cells, are increased in the skin tissues of rosacea (52,56). The release of interferon-γ (IFN-γ ) and IL-17 from the T cells stimulates the production of inflammatory lesions and angiogenesis in rosacea (57). The processing and presentation of antigenic peptides on MCs lead to the expansion of CD4 + T cells.…”

Childhood rosacea and related disorders

“…Recently, in addition to the abnormal function of the innate immune system, the role of adaptive immunity has been highlighted, with special focus on interleukin (IL)‐17, which is secreted mainly by T cells but also by innate immune cells such as macrophages, dendritic cells, natural killer cells and neutrophilic granulocytes 9 …”