Lyme Pseudothrombophlebitis Mimics Deep Vein Thrombosis in Child

Child presented with severe calf pain
Lyme pseudothrombophlebitis mimicked deep vein thrombosis
Imaging and testing led to the correct diagnosis

An 8-year-old boy with Lyme disease presented with symptoms that closely resembled deep vein thrombosis (DVT), highlighting the importance of careful evaluation when children develop unexplained calf pain and swelling.

The pain had been ongoing for one week. “He described the pain as throbbing, worse with movement, and improved with rest,” write Sandelich and colleagues.

Three days earlier, the boy had visited a different emergency department and was diagnosed with a muscle sprain following results from an X-ray.

The boy’s pain, however, continued, and an ultrasound of the lower extremity was obtained. It revealed “a 13 x 6 x 2.7-cm heterogeneous mass with solid and cystic components in the left calf,” write Sandelich and colleagues.

Imaging Revealed Myositis and a Large Calf Mass

An MRI revealed a large collection in the left gastrocnemius muscle with surrounding myositis involving the gastrocnemius muscle.

Pseudothrombophlebitis is a condition that can closely resemble deep vein thrombosis, often requiring imaging studies to distinguish between the two diagnoses. Despite the similar symptoms, pseudothrombophlebitis is not itself a deep vein blood clot.

The orthopedic team drained and irrigated the child’s knee effusion and the collection in the gastrocnemius muscle. Lyme serology testing, including testing of aspirated fluid, led to the diagnosis of Lyme pseudothrombophlebitis.

Successful Treatment for Lyme Pseudothrombophlebitis

He was treated successfully with intravenous cefazolin, followed by 4 weeks of amoxicillin.

“A known complication of a ruptured popliteal cyst is a pseudothrombophlebitis,” explain Sandelich and colleagues. A popliteal cyst, also known as a Baker’s cyst, has been reported in Lyme arthritis.

When Lyme Disease Mimics Deep Vein Thrombosis

The authors caution, “The clinical presentation in this case is similar to that of a DVT [deep venous thrombosis], and obtaining an ultrasound of the deep leg veins is imperative.”

This case illustrates how Lyme disease may occasionally present with findings that mimic other serious conditions, making imaging studies and careful clinical evaluation essential.

Frequently Asked Questions

Can Lyme disease mimic deep vein thrombosis?

Yes. In this case, Lyme pseudothrombophlebitis produced calf pain and swelling similar to deep vein thrombosis, highlighting the importance of ultrasound evaluation and careful diagnosis.

Does Lyme disease cause blood clots?

This case did not involve a deep vein blood clot. Lyme-associated pseudothrombophlebitis can produce symptoms resembling DVT, but imaging is needed to distinguish between the conditions.

What is pseudothrombophlebitis?

Pseudothrombophlebitis is a condition that resembles deep vein thrombosis without an actual deep vein clot. It may occur when a popliteal or Baker’s cyst ruptures and fluid extends into the calf.

How was the child diagnosed?

The diagnosis was made after ultrasound and MRI findings, drainage of the knee and calf collections, and Lyme serology testing that included aspirated fluid.

Clinical Takeaway

Lyme pseudothrombophlebitis is an uncommon presentation that may resemble deep vein thrombosis in children. Acute calf pain and swelling require prompt medical evaluation because DVT, infection, and other serious conditions must be excluded.

When a child presents with persistent calf pain, swelling, or imaging abnormalities suggestive of DVT, clinicians should consider Lyme disease in the differential diagnosis, particularly in endemic areas.

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References

Sandelich S, DePiero A. An Interesting Presentation of Lyme Pseudothrombophlebitis. Pediatr Emerg Care. 2019;35(5):e93-e95.

Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention