Ustekinumab associated chronic eosinophilic pneumonia

Area of Science:

• Pulmonology
• Pharmacology
• Rheumatology

Background:

• Ustekinumab is a biologic therapy used for autoimmune diseases like Crohn's disease and psoriatic arthritis.
• Drug-induced lung diseases are uncommon but can present with diverse respiratory symptoms.
• Eosinophilic pneumonia is a rare adverse effect associated with certain medications.

Observation:

• A 60-year-old female developed shortness of breath and cough after initiating ustekinumab for psoriatic arthritis and Crohn's disease.
• Diagnostic workup revealed peripheral eosinophilia and characteristic lung nodules and reticulations on CT scan.
• Bronchoalveolar lavage fluid showed a high eosinophil count, leading to a diagnosis of eosinophilic pneumonia secondary to ustekinumab.

Findings:

• The patient was diagnosed with chronic eosinophilic pneumonia (CEP) attributed to ustekinumab.
• Discontinuation of ustekinumab and treatment with high-dose prednisone resulted in resolution of symptoms and radiographic findings.
• Recovery required a prolonged tapering course of corticosteroids over five months.

Implications:

• This case underscores the importance of considering drug-induced lung disease in patients presenting with respiratory symptoms, even without a clear temporal link to drug initiation.
• The long elimination half-life of ustekinumab may contribute to persistent symptoms after drug cessation, necessitating extended treatment and patient reassurance.
• This report adds to the limited literature on ustekinumab-induced eosinophilic pneumonia, emphasizing the need for increased awareness among clinicians.