Differences between the pediatric and adult presentation of fibromuscular dysplasia: results from the US Registry.

Background: Fibromuscular dysplasia (FMD) is a non-inflammatory arteriopathy that causes significant morbidity in children.

Methods: The clinical features, presenting symptoms, and vascular beds involved are reviewed in the first 33 patients aged <18 years who are enrolled in the United States Registry for FMD from five registry sites and compared with 999 adult patients from 12 registry sites.

Results: Mean age at diagnosis was 8.4 ± 4.8 years (16 days to 17 years). Compared with adults, pediatric FMD occurs in more males (42.4 vs 6 %, p < 0.001). Children with FMD have a stronger previous history of hypertension (93.9 vs 69.9 %, p = 0.002). Hypertension (100 %), headache (55 %), and abdominal bruits (10.7 %) were the most common presenting signs and symptoms. FMD affects renal vasculature in almost all children (97 vs 69.7 %, p = 0.003). The extra-cranial carotid vessels are less commonly involved in children (23.1 vs 73.3 %, p < 0.001). The mesenteric arteries (38.9 vs 16.2 %, p = 0.02) and aorta (26.3 vs 2.4 %, p < 0.001) are more commonly involved in children.

Conclusions: In the United States Registry for FMD, pediatric FMD affects children from infancy throughout childhood. All children presented with hypertension and many presented with headache and abdominal bruits. In children, FMD most commonly affects the renal vasculature, but also frequently involves the mesenteric arteries and abdominal aorta; the carotid vessels are less frequently involved.