Suggest Treatment For Red Itching Skin Behind Ear

Hi I have been prescribed tetralysal 300mg for rosacea and I also have red itching skin behind my ear and my inner ear is itchy. My scalp is also very itchy and sore to touch and my hair has been thinning. I am a 45 year old woman. Can you tell me what this might be and is the tetralysal causing this. Is it seborrheic dermatitis. Thanks.