Background: Psoriatic Arthritis (PsA) is a chronic inflammatory disease that may affect
different joints. Sarcoidosis is a Th-1 cell-related chronic granulomatous disease characterized by
non-caseating granuloma formation. The coexistence of both the diseases is a rare entity. Ustekinumab,
an IL12 / 23 inhibitor, has shown efficacy and safety in the treatment of PsA.
Objective: This study presents a case with ustekinumab-induced sarcoidosis in a patient with PsA.
Case Report: A 52 years old female patient with complaints of pain and swelling of the wrists,
MCP, PIP and DIP joints and skin lesions was referred to our Rheumatology clinic. On her medical
history, she had been under follow up for 5 years with the diagnosis of psoriasis and one year ago, she
started to receive ustekinumab prescribed by a dermatologist. On physical examination, she had psoriasis
skin lesions and arthritis of both wrists, MCP, PIP, DIP joints. Bilateral hilar lymphadenopathies
were detected in the chest X-ray and thorax computed tomography. In laboratory tests, acute phase reactants
and serum angiotensin-converting enzyme levels were high. Endobronchial ultrasonography
biopsy was performed and non-caseating granuloma consistent with sarcoidosis was reported. Ustekinumab
was discontinued, methotrexate and low-dose corticosteroid were started. The patient was clinically
stable in the 6th month of the treatment and the findings were regressed.
Conclusion: Sarcoidosis development appears to be a new paradoxical effect of ustekinumab therapy,
being another biological agent.