Hello, my problem is that on my back below the neck many pimpals and black blots makes when the pimple blast so please help me , which medicine i can ?

Acne: Pustular pimples and black heads are a form of bacterial skin infections . There are many types of antibiotics to treat this. You may need to see your medical provider for them. Till then try warn soapy water scrubs; and apply witch hazel or rubbing alcohol to dry them out. Dr. Bronners' organic liquid soap have been very helpful for many of my patients.

Sebaceous glands,: which are not emptying, commonly called blackheads. Best is daily repeated cleansing of skin with soap, water & "soft" brush (thick baking soda/water mix & sweating can also help) to dissolve the sebum before it thickens, oxidizes (the black color) & further blocks the opening of each gland. Longer soaking with very warm/hot solution, at first, will help dissolve the oxidized sebum.