Concurrent pyoderma gangrenosum and Takayasu arteritis in an infant: diagnostic challenges and treatment considerations.

Background: Takayasu arteritis (TA) is an uncommon chronic inflammatory and autoimmune disease primarily affecting large vessels, particularly the aorta and its branches. Skin manifestations have been documented in association with TA. Pyoderma gangrenosum (PG) is a chronic neutrophilic dermatosis characterized by destructive, necrotizing, and painful ulcers, predominantly found on the lower extremities. The coexistence of PG and TA is extremely rare, with most reported cases involving adult patients. Interestingly, the association between PG and TA appears to be more common in Japan compared to North American and European populations. Childhood TA (c-TA) accompanied by PG is exceptionally rare, with only 10 cases reported in the literature thus far.

Case report: We present the case of a 7-month-old patient initially diagnosed with PG. Despite aggressive immunosuppressive therapy, the patient`s high acute phase reactants remained elevated. Although the abdominal ultrasound was normal, advanced imaging was performed due to severe abdominal pain. Contrastenhanced computerized tomography angiography of the aorta and its branches revealed extensive vascular involvement consistent with TA.

Conclusion: In this report, we highlight an infantile case of PG that was subsequently diagnosed as infantile TA. Recognizing the rare association between PG and TA is important. Thorough evaluation and prompt diagnosis of TA in infants with PG can guide further investigations and prevent vascular complications.