Hi there. From your history & clinical description, these appear to be acneiform lesions. Acneiform lesions on the buttocks can be something as simple as a 'follicular keratoses' associated with dry skin
syndromes or some sort of viral infection as in molluscum contagiosum
that appear as per your description but with some 'dimpling' in the centre & are usually described as pearly white but in clinical experience that can vary. It is best that you set up an appointment with a dermatologist
nearest you or if you should choose to, please upload your photographs using the 'upload data' icon on this screen & we could give you a much clearer picture. Should you desire privacy, please feel free to use our premier 'ask-a-specialist' feature & you can get in touch with me privately & we can take it from there. The treatment will depend on the cause & can vary from use of a cream to minor surgical or electrosurgical excision as an out-patient procedure. Cheers & good luck!
Dr Praveen Rodrigues MD
Dermatologist, Cosmetologist, Venereologist
Vikram Hospital, Bangalore, India