# Small-Vessel Thrombotic Vasculopathy Secondary to Paradoxical Emboli Traversing a Patent Foramen Ovale: A Vasculitis Mimic

## TL;DR

A young man's foot symptoms were caused by blood clots from a heart defect, mimicking vasculitis, highlighting the need for heart imaging in similar cases.

## Contribution

This case is the first to describe small-vessel injury caused by paradoxical emboli through a patent foramen ovale.

## Key findings

- A 20-year-old male presented with small-vessel ischaemia mimicking vasculitis.
- Histopathology revealed acute thrombotic vasculopathy, not vasculitis.
- A patent foramen ovale was identified as the source of paradoxical emboli.

## Abstract

Paradoxical thromboembolism via intracardiac defects have been described to cause limb ischaemia by occluding medium- to large-vessels. No cases have described injury to only the small vessels of the feet. We present a case of a 20-year-old male presenting with painful dusky digits of both feet who was initially thought to have a small-vessel vasculitis, but instead found on histopathological examination to have acute thrombotic vasculopathy causing cutaneous ischaemia. He was subsequently found to have a patent foramen ovale (PFO) but no thrombosis elsewhere. This case underscores the importance of transthoracic echocardiography (TTE) in patients presenting with small-vessel ischaemia, even in the absence of deep venous thromboses.