Suggest Treatment For Red Rashes And Pimples On Shoulder

i had bactrim rash,after it cleared up rash was red on my shoulders no raised pimples,doctor gave me preginose foe week.now i have raised red pimples about 20 that itch.tried cortizone ointment no good.they did biopsy showed dermatitis.2 dermatologists dont know what the res bumps that itch arePlease type your query here...