Thanks for posting the qwery.
These rashes might be due to drug allergy
or seborrhoeic dermatitis
Drug allergy may be due to medications you are taking for fibromyalgia
. If you withdraw the offending medications, your symptoms might subside. Seborrhoeic dermatitis can be tackled by proper antifungal lotions and creams.
Take antihistamines I.e. anti allergic medicines and topical moisturising creams along with calamine lotion to reduce itchiness and discomfort.
Proper dermatological evaluation of this condition is necessary.
Hope for speedy recovery.