The Compendium of Caraka 5.9.20

5.9.20

pittamūṣmānugaṃ yasya śaṅgau prāpya &vimūrcchati/
sa rogaḥ śaṅkhako nāmnā trirātrāddhanti jīvitam//

In whom pitta accompanied by body heat reaches the temples and faints:
that disease, called śaṅkhaka, destroys life in three nights.