To be precise i find pimples on my buttocks which leads to darken my skin.... i feel no itching or irritating sensations.

Skin lesions: Skin related "pimples" or lesions are hard if not impossible) to diagnosis over the computer. See a dr. To get physically examined, and the diagnosis and treatment will follow.

Folliculitis: It is not uncommon for one to have pimples on the buttocks that develop form blocked hair follicles , worsened by sweating and pressure from clothing (and prolonged sitting). Oftentimes as the pimples resolve , the pimples become bumps and eventually can flatten but can remain discolored for months or years.