From 4-5 months, there's a crawling sensation on my back near shoulders with small pimple like things and itching, when i rub ends in either numbness or burning sensation,now that pimple kind things are spreading near underarms.any serious condition?

Doctor can examine: Bumps and spots can be from many causes, such as: hives, viral infections, other infections (impetigo), medication causes, hot-tub rashes, heat rashes, reactions to creams or lotions, allergic reactions to various things (poison oak, allergenic foods), etc... That means a rash that persists, looks worrisome, or may be infected should be checked by a doctor... in-person or online.