'My entire scalp was on fire': A doctor repeatedly insisted she had a tension headache. Something more serious was going on.

Galen Warden was lying in a hot bath after a punishing week at her demanding marketing job. Her neck and shoulders were, as usual, in knots, so Warden thought she’d expedite the relaxation that a restorative soak usually delivered by sliding under the water. When she sat up about 30 seconds later, Warden recalled, “it felt like my entire scalp was on fire.” Her face, neck and shoulders were unaffected, but her scalp felt as though it had been doused with acid.