Itch
An itch was a mild skin  that could be alleviated by scratching.

According to Q, having an itch was one of the disadvantages of being Human. ()

Inkarian wool was known for being itchy. ()

Itching was also a metaphor for eagerness to do something. (, ,  )

In 2151, Hoshi Sato complained that her fake Akaali ridges made her forehead itch. ()

After escaping from the Tandaran internment camp in 2152, Malcolm Reed told T'Pol to ask Doctor Phlox to meet him and Jonathan Archer in sickbay, complaining of itchy skin. ()

In 2153, a recovering Jonathan Archer was kept up all night by itching. He told Doctor Phlox this, and the Denobulan asked him if he was using the ointment he gave him. He also advised the captain that scratching would prolong the healing process. ()

In 2258 of the alternate reality, following a vaccination for the viral infection caused by Melvaran mud fleas, , suffering from an allergic reaction, complained that his mouth was itchy and asked if that was normal.  assured him that those symptoms wouldn't last very long. ()

While camping in the Gamma Quadrant in 2370, Quark complained that his ears itched. () 

In 2371, an immobilized Neelix asked The Doctor to scratch an itch above his left eyebrow. ()

In 2372, a pregnant Kira Nerys's nose had been itching for weeks. ()

In 2373, Tom Paris complained that the clamp made him itch like crazy. ()

In 2374, Neelix finished Tuvok's suggestion that he ask The Doctor for anti-itch cream to deal with the rash he claimed Starfleet blankets gave him. ()

In 2377, Chakotay's excuse for not posing as a Talaxian was that whiskers made him itch. ()

Sometimes allergies could cause itchiness. Icoberry juice made Jadzia Dax's spots itch. Worf reminded her of this, but she decided to have a glass anyway. ()

Irritating chemicals could also cause itchiness. In 2372, Neelix's scalp itched due to shampoo. () Also that year, trigemic vapors leaking into their crashed shuttlecraft made Paris and Neelix itch. ()

Icheb disliked being called "Itchy" by Q Junior, so much so that he requested the  not refer to him as such in front of Voyagers senior officers. ()

See also
 Itching powder

External link
 
Medical conditions