Paradoxical Eczematous Reaction in a Patient With IL-17 Inhibitor-Treated Psoriasis Vulgaris.

Psoriasis is a chronic dermatologic condition that oftentimes requires extensive trial and error with various topical and systemic therapies until improvement is achieved. Interleukin-17 inhibitors (IL-17i), such as secukinumab, have been utilized in the treatment of psoriasis due to their mechanism of action. As with all medications, IL-17 inhibitors possess adverse effects, the most common being infection, nasopharyngitis, and injection site reaction. However, one rare adverse event, the paradoxical eczematous reaction, has been known to occur among patients on biologics including IL-17 inhibitors. Although it is a rare occurrence, our paper stresses the importance of educating patients about this potential side effect, the benefits and risks of starting a biologic, and obtaining informed consent from the patient. We present a case of a 14-year-old male with recalcitrant psoriasis vulgaris who developed a paradoxical eczematous reaction while undergoing treatment with secukinumab.