Objective:

This case highlights the importance of the physical exam and advanced imaging in an infant with a history of fevers of unknown origin.

Background:

Congenital dermal sinus tract is a rare form of closed neural tube defect, connecting the epidermis to a deeper layer. This connection between the outside world and the spinal cord is a nidus for bacterial meningitis and other infections, and dedicated imaging is essential in identifying such a tract.

Design/Methods:

NA

Results:

A 9-month-old previously healthy male repeatedly presented with intermittent fevers despite recurrent antibiotics. Cerebrospinal fluid (CSF) analysis demonstrated neutrophilic pleocytosis, elevated protein, and hypoglycorrhachia while extensive testing for autoimmune etiologies of fever was normal. Whole-body MRI and head CT were negative. He developed altered mental status and CSF continued to suggest bacterial meningitis; CSF cultures grew Propionibacterium. Imaging showed hydrocephalus, and an external ventricular drain was placed. A dedicated MRI of the brain and spine was obtained, revealing debris in the lateral ventricles, ventriculitis, leptomeningitis, and a sacral dermal sinus tract with an associated intradural cyst extending from L5-S4. This finding was correlated with a small midline sacral dimple. The patient underwent correction of the dermal sinus tract and removal of the cyst. He improved with ceftriaxone and metronidazole along with placement of a ventriculoperitoneal shunt.

Conclusions:

This case emphasizes the role of the physical exam in infants, especially the examination of the spine. Recurrent CSF findings consistent with bacterial meningitis warrant investigation for a source, including a thorough physical exam and detailed imaging, especially a dedicated spine MRI, regardless of a previous, whole-body MRI. Even with access to such exceptional diagnostic testing, no test is perfect. When findings repeatedly point toward a specific disease process, clinicians should continue investigating the underlying source rather than looking for rarer alternatives.