Hobo Kostinen had alopecia. (PROSE: Avatars of the Intelligence)
Alopecia, also known as baldness, was a condition where an individual's hair on the top of their head began to recede with age or was absent due to other reasons. It could be acute, such as a small loss of hair, or advance to the point where someone did not have any hair at all. Baldness could also be a hairstyle by choice, afflicted by physical scarring, (TV: The Caves of Androzani) radiation, (TV: The Mutants) or due to biological experimentation that removed hair. (WC: The Making of the Gunslinger, TV: A Town Called Mercy)
Baldness in individuals[]
When he had grown quite older, the First Doctor appeared to have some degree of baldness, with most of his hair growing around the back of his head. (TV: An Unearthly Child)
When Peri Brown was selected for brain surgery, she was forcibly shaved bald in preparation. (TV: Mindwarp)
The Fifth Doctor gained a temporary bald spot when the time differential in a future version of his TARDIS caused him to age very quickly. (TV: Time Crash)
When the Tenth Doctor was forced to age by the Master, he went partially bald. The second time he was aged, he went completely bald. (TV: The Sound of Drums, Last of the Time Lords)
The Eleventh Doctor once got bored and shaved his head with a razor. However, it allowed him to wear a wig and hide a TARDIS key in his coif that Tasha Lem could not discover when he set foot on a planet with a technology ban. He also exhibited true baldness at the echelon of old age. This condition reversed when his new regeneration cycle reset him back to a youthful body. (TV: The Time of the Doctor)
Though Nardole appeared to be bald, (TV: The Husbands of River Song et al.) his glass avatar would claim that he actually had invisible hair. (TV: Twice Upon a Time)
Hobo Kostinen had alopecia, (PROSE: Avatars of the Intelligence) which he had been bullied for. (PROSE: 8.46)
After the Time Lords resurrected him, the Master's new incarnation was totally bald. The Eighth Doctor ridiculed him because of it. (AUDIO: Eyes of the Master)
Baldness in species[]
Sontarans, at least in the case of their clone batch-borne warriors, were naturally bald. (TV: The Time Monster, The Sontaran Experiment, et al.) However, some could have vestigial hair such as beards that turned white with age like those of humans. (PROSE: Shakedown) Strax, a Sontaran, didn't understand the growth of hair on humans and other species; he once mistakenly thought River Song's curly hair meant she had a big head. Clara Oswald subsequently referred to River as "the lady with the funny name and the space hair". (TV: The Name of the Doctor)
Other species which appeared to be naturally bald included the Rostrow, (COMIC: Mission for Duh) the Technix, (TV: The Daleks' Master Plan) the Yend (PROSE: The Sons of the Crab) and the natives of Jevo. (COMIC: The Emissaries of Jevo)
Behind the scenes[]
Matt Lucas, who played Nardole, has alopecia.
