Eosinophilia Induced by Biosimilar Adalimumab (CinnoRA) in a Patient with Psoriasis and Psoriatic Arthritis: A Case Report.

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder that can significantly impact quality of life. Biologic therapies, such as TNF-alpha inhibitors, have improved clinical outcomes but may rarely cause hematologic abnormalities, including eosinophilia. Eosinophilia is uncommon but can be associated with allergic reactions or organ involvement.

CASE PRESENTATION

We report a 33-year-old male with psoriasis and psoriatic arthritis who developed asymptomatic marked eosinophilia after eight doses of biosimilar adalimumab (CinnoRA). Baseline peripheral blood eosinophil percentage was 3.2%, which increased to 19.9% during therapy. Alternative causes, including parasitic infection, allergy, and hematologic disease, were excluded. CinnoRA was discontinued, and eosinophil counts normalized during follow-up.

CONCLUSION

This case illustrates that unexplained eosinophilia can occur during TNF-alpha inhibitor therapy. While routine monitoring is not universally recommended based on a single case, clinicians should consider eosinophilia as a possible adverse reaction, especially in symptomatic patients or those with persistently elevated counts.