Presentation
A 28-year-old man with major depressive disorder maintained on fluoxetine presents with 8 hours of worsening agitation, generalized tremor, and drenching sweats. Two days ago his primary care provider added tramadol for acute low back pain. He is restless and diaphoretic with dilated pupils and brisk reflexes.
Initial observations
- T 39.2 C (102.6 F)
- HR 122
- BP 158/96
- RR 22
- SpO2 98% on room air
- fingerstick glucose 104
Which single examination finding best distinguishes this presentation from neuroleptic malignant syndrome (NMS) and anticholinergic toxicity?