Anna, a 28-year-old first-time mother, presents to the clinic with complaints of breast pain and fever. She is 3 weeks postpartum and breastfeeding her newborn. She reports pain and swelling in her left breast for the past two days, accompanied by redness in the upper outer quadrant. She also notes feeling fatigued, having chills, and a fever of 38.9°C (102°F). Anna mentions that her baby has been struggling with latching, leading to prolonged feedings and occasional engorgement. Examination: General Appearance: Fatigued but alert. Vital Signs: Temperature: 101.2°F, Pulse: 90 bpm. Breast Exam: Left breast: Redness, swelling, and tenderness in the upper outer quadrant; warm to touch, no fluctuance. Right breast: Normal; no cracked nipples or visible wounds. What is the most common cause of lactational mastitis?
