17th February 2025

A 54-year-old lady presents with deteriorating asthma despite taking salbutamol, budesonide and montelukast.

A 54-year-old lady presents with deteriorating asthma despite taking salbutamol, budesonide and montelukast. On examination, she has reduced sensation in both feet. She reports a history of frequent colds and headaches over the past few years.

Blood tests: 

Hb 120 [115-165 g/L]

WCC 11 [3.5-11 x 10^9/L]

Neutrophils 7 [1.8-7.5 x 10^9/L]

Eosinophils 3 [0.1-0.4 x 10^9/L]

CRP 40 [<5 mg/L]

U&Es within normal limits

What test would be helpful to establish the likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.