You might have noticed some images of Goddess Bhadrakali having dots or poxes on her face. There is an interesting story as to why she has poxes only on her face. The story is associated with wife of Demon Mahishasura found in folklore especially in North Kerala.
Manodari, the wife of Demon Mahishasura, performed intense austerities to please Shiva. Her sole aim was to avenge Goddess Bhadrakali who had killed her husband. Shiva was not ready to appear before Manodari but Goddess Parvati insisted that He should appear before the wife of the demon.
Shiva decided to appear only for a few seconds. Within that few seconds, Manodari asked for the sweat that fell from the body of Shiva.
Shiva gave her his sweat and disappeared. Manodari returned back and saw Goddess Bhadrakali walking away happily after the war against her husband. She decided to test the power of the sweat and threw some of it on Bhadrakali. Goddess Bhadrakali was inflicted with pox. She started losing her strength and soon fell down.
Shiva who came to hear about this horrific event got up in anger and transformed into his Raudra form. Suddenly a murti took birth in his throat or Khanda and it came out from the cheek of Shiva. This murti was named Khandakarnan. He immediately went to Goddess Bhadrakali and licked her body and this freed her from the pox. When Khandakarnan moved to lick the face of Goddess Bhadrakali, she stopped his saying that they were brother and sister and he should not do it. Bhadrakali decided to wear the poxes on her face as a makeup or beauty spot.