O91.21 Nonpurulent mastitis associated with pregnancy

Name of the Condition

• Nonpurulent Mastitis Associated with Pregnancy (O91.21)

Summary

This condition involves inflammation of the breast tissue during pregnancy that is not associated with pus formation. It may present with localized pain, swelling, or redness and requires evaluation to distinguish from infectious causes. Management focuses on symptom relief and monitoring for progression.

Causes

Nonpurulent mastitis during pregnancy is often linked to hormonal changes, milk duct engorgement, or mechanical irritation. Unlike purulent forms, it typically lacks bacterial infection, though inflammation may still occur due to milk stasis or tissue trauma.

Risk Factors

• Hormonal fluctuations in pregnancy.
• Engorgement or blocked milk ducts.
• Previous breast inflammation.
• Mechanical irritation from clothing or activity.

Symptoms

• Breast pain, tenderness, or swelling.
• Redness or warmth in the affected area.
• Mild systemic symptoms (e.g., low-grade fever).
• Absence of pus or significant discharge.

Diagnosis

Diagnosis is clinical, based on physical examination and symptom assessment. Cultures are generally not required unless infection is suspected. Imaging (e.g., ultrasound) may be used to rule out abscess or other complications.

Treatment Options

• Warm compresses to relieve discomfort.
• Gentle breast massage to improve milk flow.
• Supportive care for symptom management.
• Antibiotics are typically unnecessary unless infection is confirmed.

Prognosis and Follow-Up

Most cases resolve with conservative measures. Follow-up may involve monitoring for symptom improvement or signs of progression to infection. Recurrence is possible with subsequent pregnancies or lactation.

Complications

• Progression to purulent mastitis or abscess.
• Persistent pain or tissue damage.
• Rarely, systemic inflammation if untreated.

Lifestyle & Prevention

• Wear supportive, non-restrictive bras.
• Avoid excessive pressure on the breasts.
• Maintain good breast hygiene.
• Address engorgement promptly with feeding or pumping.

When to Seek Professional Help

Seek care if symptoms worsen, fever develops, or pus is present. Persistent pain or lack of improvement after 24–48 hours warrants evaluation.

Tips for Medical Coders

Document clinical findings to confirm nonpurulent inflammation, including absence of pus or bacterial infection. Ensure the pregnancy context is clearly recorded, as this code is specific to pregnancy-related mastitis without purulence.