# Familial Deep Vein Thrombosis in a Child With Antithrombin III Deficiency: A Case Report

## TL;DR

A child with no obvious cause of leg pain and swelling was diagnosed with deep vein thrombosis and found to have antithrombin III deficiency, a rare inherited condition.

## Contribution

This case report highlights a rare pediatric DVT case with antithrombin III deficiency and a family history of thrombosis.

## Key findings

- An 8-year-old girl presented with leg pain and swelling, leading to a DVT diagnosis.
- Thrombophilia testing revealed antithrombin III deficiency as the underlying cause.
- Treatment with heparin and rivaroxaban improved the patient's symptoms.

## Abstract

Deep vein thrombosis (DVT) is caused by a clot (thrombus) formed in the deep veins, usually the legs. The incidence of DVT is notably less prevalent in children than in adults. Here, we present a rare case of DVT in an eight-year-old female child with a significant family history involving the untimely death of the maternal aunt. The child presented with pain and edema in the left lower limb causing immobilization without any obvious cause. The clinical features suggested the possibility of DVT. On further evaluation and radiological investigations, the diagnosis of DVT was confirmed. A complete thrombophilia workup was done showing antithrombin (AT) III deficiency. The patient was then started on low-molecular-weight heparin, leading to improvement in the symptoms. Oral rivaroxaban was continued for the patient on discharge.