Final answer:
Instruct her to continue breastfeeding and start oral cephalexin (Answer: B). This patient is most likely presenting with mastitis, an infection of the breast tissue commonly seen in women who are breastfeeding. The initial management of mastitis involves continuing breastfeeding and starting antibiotics to treat the infection.
Step-by-step explanation:
The next step in the management of this patient is to Instruct her to continue breastfeeding and start oral cephalexin (Answer: B)
This patient is most likely presenting with mastitis, which is an infection of the breast tissue commonly seen in women who are breastfeeding. The presenting symptoms include pain and swelling of the breast, fever, and myalgias. The initial management of mastitis includes continuing breastfeeding to help drain the breast and starting antibiotics to treat the infection.
Cephalexin is a first-line antibiotic choice for the treatment of mastitis. It is safe to use during breastfeeding and effectively treats most common pathogens that cause mastitis, such as Staphylococcus aureus.
Intravenous vancomycin would be reserved for severe cases of mastitis where the patient is unable to tolerate oral antibiotics or if the infection does not respond to initial treatment with cephalexin.