‘A pain in the back’: Psoas abscess and the importance of red and yellow flags

The following article is a case presentation of a patient encountered by the author whist working in the Emergency Department (ED). The patient presented with low back pain, and had been treated in primary care conservatively with analgesia. However during his assessment in ED he was found to have symptoms suggestive of Sepsis, and following further investigations an Ileopsoas Abscess (IPA) was discovered. A brief overview of the case if presented along with a discussion of the pathophysiology and management of IPA. Whilst IPA is a rare presentation, this case articulates the importance of red and yellow flags in the assessment of low back pain.

A 19 year old man attended an ED in Wales (UK) with an eleven day history of low back pain. Following a five mile walk he developed bilateral heaviness in his legs, one day later he experienced gradual onset of left sided low back pain radiating into his left buttock. He attended his GP who prescribed oral analgesia and diazepam. His pain increased in the following days, and he was advised to lie on the floor, which he did for the following three days. He later became unable to stand, and reported passing dark coloured offensive urine. The patient reported no saddle anaesthesia, incontinence, or paraesthesia.