I take biotin 10,000 mcg solgar. and so far i'm breaking out so much and getting painful itchy back acne. help? i need biotin for hair loss nd thining

Not the biotin: biotin is used to help with hair loss and nail growth as well as some skin conditions. It should not cause back acne or rashes unless you are allergic to it. You can try decreasing the dose or holding it for a few weeks to see if your acne improves but if it doesn't you should see your doctor to discuss causes and treatment options.