Generating hand dysaesthesiae: the "GHD phenomenon" - straight to the diagnosis

Two Irish women presented with difficulty in completion of hair straightening, limited by upper limb dysaesthesiae due to claudication or brachial plexus entrapment induced by sustained shoulder abduction beyond 90 degrees. The first described arm pain precipitated by elevation and sustained abduction above shoulder level, particularly while using her GHD hair-straightener. Elevated arm stress test was positive and a left cervical rib was seen on chest x ray. Neurogenic thoracic outlet syndrome (TOS) was diagnosed and the cervical rib was resected. The second described arm tingling and weakness when performing tasks involving shoulder abduction and elevation, limiting GHD use to 10 min before having to rest. Upper limb blood pressure and pulses were undetectable. Erythrocyte sedimentation rate was elevated and flow on radial Doppler disappeared on abduction and elevation of each arm. A CT pulmonary angiography demonstrated features of Takayasu's arteritis. Vascular TOS was diagnosed. Symptoms resolved with corticosteroids, followed by long-term immunosuppression and anti-coagulation.