Atopic Dermatitis Flare Following Initiation of Nemolizumab

Atopic dermatitis (AD) is a chronic inflammatory skin disorder marked by intense pruritus and episodic flares. While nemolizumab, an interleukin-31 (IL-31) inhibitor, has demonstrated efficacy in reducing itch severity, its broader effects on skin inflammation are not fully understood.

We describe a 49-year-old male with longstanding, treatment-resistant AD who began off-label therapy with nemolizumab. Within weeks of initiation, he developed a new pruritic vesiculobullous eruption localized to the palms, clinically and histologically consistent with dyshidrotic eczema. His prior AD lesions remained stable, but the new eruption prompted temporary discontinuation of nemolizumab.

The patient was treated with intravenous corticosteroids, resulting in significant improvement of the dyshidrotic eczema.

This case highlights the potential for nemolizumab to exacerbate AD in some patients, emphasizing the need for caution and further research on its inflammatory effects and safety in real-world settings.