Pediatric Psoas Abscess, Early Diagnosis of a Challenging Condition

Psoas abscess is a rare entity at the pediatric stage of life. The clinical presentation of psoas abscess is insidious and not specifi c, and this usually causes diagnostic delay. Early diagnosis is relevant to prevent devastating consequences of this condition.

This study aimed to describe the natural history of psoas abscess, present our experience in a children's hospital, determine warning signs and symptoms that may lead to early diagnosis, and describe differential diagnoses. We also discuss the devastating consequences of misdiagnosing psoas abscess.

This retrospective study was performed at Sant Joan de Déu Children's Hospital (Barcelona, Spain) from 2008 to 2016. All patients younger than 18 years old (n = 12) with psoas abscess who were diagnosed by imaging tests were included.

The initial clinical presentation of the patients was variable. Painful hip mobility at extension (7 cases), limping (5 cases), and fever (4 cases) were the most frequent presentations. Laboratory parameters were abnormal in nine patients. The main responsible bacteria was Staphylococcus aureus (9 cases). The mean hospital stay was 28 days (range, 10-71 days). Percutaneous drainage under ultrasound control was applied in two patients. Surgical debridement was performed in seven patients, and repeated procedures were required in three of them.

Because of the erratic presentation of psoas abscess, its suspected diagnosis is essential for an early diagnosis, which will minimize the risk of diagnostic delay. One or more signs and symptoms at the same time might be considered as initiation of psoas abscess. Physicians should be aware of risk factors, such as previous traumatism and a known disturbed immunological system or temporal circumstances, which might lead to psoas abscess. Laboratory parameters may provide more confi dence in diagnosis, and early imaging tests provide a defi nitive diagnosis.