Tacrolimus Ophthalmic Suspension Can Be an Effective Treatment Option for Biologic-Induced Refractory Conjunctivitis.

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease characterized by intense pruritus. It is a multifactorial condition involving complex interactions among skin barrier dysfunction, immune dysregulation, genetic predisposition, and alterations in the skin microbiome. The disease is primarily driven by Th2-associated cytokines such as interleukin (IL)-4, IL-13, and IL-31, which contribute to inflammation and exacerbate pruritus, perpetuating the "itch-scratch cycle." Recently, biologics targeting Th2 cytokines - such as dupilumab, lebrikizumab, and tralokinumab - have emerged as effective treatment options for moderate-to-severe AD. Conjunctivitis is a common adverse effect associated with biologic therapies. In severe cases of conjunctivitis, continuation of biologic therapy may be difficult, highlighting the importance of appropriate ophthalmologic management. Herein, we report a case of AD successfully controlled with lebrikizumab, in which the patient developed conjunctivitis refractory to artificial tears and fluorometholone eye drops. Switching to tacrolimus ophthalmic suspension resulted in marked improvement. While tacrolimus eye drops are not approved for conjunctivitis, they are indicated for vernal keratoconjunctivitis and may be considered in severe cases of AD-related conjunctivitis in consultation with ophthalmologists.