Hi, Could there be a physical cause for the recurrent mastitis in the 7 month old's mom? Sleeping on the left side, purse strap, back pack, diaper bag, bra, anything tight or restricting can cause recurrent mastitis like this. Look for a physical cause, it may take some good detective work. Sincerely, Sharon A. Rapoza, RN, BSN, IBCLC Breastfeeding Works LC Service