Periductal Mastitis (Non-Lactational)

1. Clinical Overview

Summary

Periductal Mastitis (PDM) is a chronic inflammatory condition of the subareolar ducts, predominantly affecting women of reproductive age, with a strong association with cigarette smoking (> 90% of cases). It is pathologically and clinically distinct from simple Duct Ectasia, a condition primarily affecting older post-menopausal women. [1,2]

The underlying pathophysiology involves smoking-induced squamous metaplasia of lactiferous duct epithelium, leading to keratin plugging, duct rupture, and secondary infection with anaerobic organisms. The clinical hallmark is recurrent subareolar abscess formation, often progressing to mammary duct fistula formation if untreated. [1,3]

PDM represents a significant diagnostic and therapeutic challenge in breast surgery, with high recurrence rates (exceeding 50%) in patients who continue smoking, even after surgical intervention. Definitive treatment requires both smoking cessation and, in recurrent cases, total excision of the subareolar duct system. [4,5]

Clinical Pearls

The "Zuska's Disease" Triad: The classic clinical picture consists of:

1. Recurrent Retroareolar Abscess.
2. Intermittent purulent discharge.
3. A cutaneous fistula at the border of the areola.

Smoking Gun: Asking a patient with periductal mastitis to stop smoking is not merely "good advice" – it constitutes the primary treatment. Surgery has a > 50% failure/recurrence rate in patients who continue to smoke, attributed to poor microvascular healing and continued duct epithelial damage. [4,5]

Anaerobic Smell: The pus from a PDM abscess is characteristically foul-smelling, reflecting polymicrobial anaerobic flora (Bacteroides, Peptostreptococcus, Staphylococcus aureus, and occasionally Enterococcus species) rather than the pure Staphylococcus aureus typical of lactational mastitis. [6]

Cancer Mimicry: Chronic periductal mastitis can present with skin tethering, nipple retraction, and an inflammatory mass that clinically and radiologically mimics inflammatory breast cancer. Core biopsy is mandatory to exclude malignancy. [7]

---

2. Epidemiology

Demographics

Risk Factors

Major Risk Factors:

• Active Smoking: Relative risk > 10; dose-dependent relationship with pack-years. [4]
• Nipple Piercing: Traumatic breach of epithelial barrier allows bacterial colonization. [9]
• Diabetes Mellitus: Impaired wound healing and immunocompromise. [10]

Moderate Risk Factors:

• Obesity: BMI > 30 associated with increased risk. [10]
• Nipple Inversion: Pre-existing anatomical variant may predispose to stasis. [2]
• Immune Suppression: HIV, chemotherapy, immunomodulatory therapy. [11]

Epidemiological Trends

The incidence of periductal mastitis has remained relatively stable over the past three decades, correlating with smoking rates in women of reproductive age. Unlike lactational mastitis, which shows seasonal variation (peak in late summer), PDM demonstrates no seasonal pattern. [12]

---

3. Aetiology and Pathophysiology

Aetiological Classification

Periductal mastitis is fundamentally a disease of squamous metaplasia induced by tobacco toxins, distinguishing it from the involutionary process of duct ectasia. [1]

Molecular Pathophysiology

Stage 1: Metaplastic Transformation Cigarette smoke contains > 7,000 chemical compounds, including polycyclic aromatic hydrocarbons, nitrosamines, and heavy metals. These toxins are concentrated in breast tissue and specifically target the terminal duct lobular unit. [13]

Chronic exposure induces the normal cuboidal/columnar epithelium of lactiferous ducts to undergo squamous metaplasia – transformation into stratified squamous epithelium resembling skin. This metaplastic epithelium produces keratin, a protein not normally synthesized by ductal epithelium. [1,2]

Stage 2: Keratin Accumulation and Obstruction Squamous cells undergo continuous desquamation, shedding keratin debris into the duct lumen. Unlike normal duct secretions, keratin cannot be effectively cleared through the nipple. Progressive keratin accumulation leads to luminal obstruction. [3]

Stage 3: Duct Dilatation (Ectasia) Proximal to the obstruction, the duct dilates as secretions accumulate behind the keratin plug. This creates a pressurized, dilated duct segment vulnerable to rupture. [2]

Stage 4: Duct Rupture With sufficient intraluminal pressure, the duct wall ruptures, spilling keratin and duct contents into the periductal stromal tissue. Keratin is highly chemotoxic to surrounding tissue. [3]

Stage 5: Granulomatous Inflammation The extravasated keratin triggers a vigorous foreign body giant cell reaction. Histologically, this manifests as granulomatous inflammation with multinucleated giant cells engulfing keratin debris. This sterile inflammatory phase may present as a tender periareolar mass. [2,3]

Stage 6: Secondary Bacterial Infection The inflammatory environment and breach in epithelial integrity allow bacterial colonization. The predominant organisms are anaerobes (Bacteroides species, Peptostreptococcus, Prevotella) alongside Staphylococcus aureus. This mixed flora reflects the proximity to skin and nipple surface flora. [6]

Stage 7: Abscess Formation Bacterial infection converts the sterile granulomatous inflammation into a purulent abscess. The abscess typically localizes to the subareolar region, corresponding to the anatomical site of major lactiferous duct convergence. [6,8]

Stage 8: Fistula Formation (Chronic Phase) If the abscess is inadequately drained or antibiotic therapy is incomplete, chronic infection persists. The abscess seeks the path of least resistance, typically tracking anteriorly to discharge through the skin at the areolar margin (the junction between areolar and normal skin). This creates a mammary duct fistula – a chronic epithelialized tract connecting the duct lumen to the skin surface. [14,15]

The fistula represents a persistent connection between the contaminated duct system and the external environment, perpetuating recurrent infection cycles. Spontaneous healing is rare once a fistula is established. [14]

Histopathological Features

Acute Phase:

• Dilated ducts filled with keratin debris
• Neutrophilic infiltration
• Periductal edema and hyperemia

Chronic Phase:

• Squamous metaplasia of duct epithelium (pathognomonic)
• Multinucleated foreign body giant cells
• Periductal fibrosis
• Plasma cell infiltration (hence the term "plasma cell mastitis")
• Epithelialized fistula tract (if present)

---

4. Differential Diagnosis

The differential diagnosis of periductal mastitis encompasses several distinct entities that present with similar periareolar inflammation:

Major Differentials

Distinguishing Features: Periductal Mastitis vs. Duct Ectasia

This distinction is critical, as these were historically conflated but represent separate pathological entities: [1]

---

5. Clinical Presentation

Acute Presentation

Cardinal Symptoms:

• Pain: Severe, throbbing retroareolar pain, often unilateral
• Erythema: Periareolar skin erythema and warmth
• Swelling: Tender, fluctuant subareolar mass
• Discharge: Purulent, thick, may be blood-stained or foul-smelling

Physical Examination Findings:

• Tender, fluctuant retroareolar mass (2-5 cm diameter typical)
• Overlying skin erythema and warmth
• Pointing sign: skin thinning at site of impending rupture
• Regional lymphadenopathy (axillary nodes palpable in 30% of cases) [8]

Systemic Features: Unlike lactational mastitis, systemic features (fever, rigors) are often mild or absent unless the abscess is large (> 5 cm) or the patient is immunocompromised. [6]

Chronic/Recurrent Presentation

Cardinal Features:

• Recurrent Abscesses: Multiple episodes in the same subareolar location
• Mammary Duct Fistula: Visible opening at areolar margin with intermittent discharge
• Nipple Inversion: Secondary to periductal fibrosis and scarring
• Indurated Mass: Chronic inflammatory mass that may mimic carcinoma

Fistula Characteristics:

• Location: Typically at the areolar-skin junction (6 o'clock position most common)
• Discharge: Intermittent purulent or serosanguinous discharge
• Probe test: A lacrimal probe can be passed from the skin opening into the duct system (positive "probe test")
• Associated erythema and induration of surrounding tissue [14,15]

Red Flag Features (Requiring Urgent Investigation)

⚠️ Inflammatory Breast Cancer Mimicry:

• Rapid progression of erythema (days rather than weeks)
• Peau d'orange (dermal edema resembling orange peel)
• Diffuse breast involvement rather than localized subareolar
• No response to appropriate antibiotic therapy after 2 weeks
• Hard, fixed mass rather than fluctuant abscess [7]

⚠️ Paget's Disease of Nipple:

• Eczematous changes of nipple-areolar complex
• Failure to respond to topical steroids
• Unilateral presentation [7]

---

6. Investigations

Initial Assessment (All Patients)

1. Clinical History:

• Smoking history (pack-years)
• Previous episodes of abscess/mastitis
• Lactation status
• Previous breast surgery or trauma
• Systemic symptoms
• Diabetes or immunosuppression

2. Breast Examination:

• Inspection: skin changes, nipple retraction, fistula openings
• Palpation: mass characteristics (size, consistency, fixation), lymphadenopathy
• Assessment of fluctuance (indicates abscess formation)

Imaging

Ultrasound (First-Line Investigation):

Indications: All patients with suspected abscess

Typical Findings:

• Hypoechoic or anechoic fluid collection with increased posterior acoustic enhancement
• Internal echogenic debris (keratin, pus)
• Surrounding hyperemia on color Doppler
• Dilated retroareolar ducts
• Size and location of abscess cavity

Sensitivity: 95% for abscess detection [16]

Clinical Utility:

• Differentiates abscess (fluid collection requiring drainage) from inflammatory phlegmon (solid inflammation)
• Guides percutaneous aspiration or drainage
• Assesses extent and multilocularity
• Excludes underlying solid mass

Mammography:

Indications:

• Age > 35 years (standard screening threshold)
• Suspicion of underlying malignancy
• Chronic recurrent inflammation

Typical Findings:

• Retroareolar density or asymmetric thickening
• Coarse calcifications (may mimic DCIS calcifications)
• Skin thickening
• Architectural distortion

Limitations:

• Inflammation reduces sensitivity for detecting malignancy
• Often deferred until acute inflammation resolves [16]

MRI Breast:

Indications (Selected Cases):

• Complex recurrent fistulae requiring surgical mapping
• Suspicion of inflammatory breast cancer (enhancement pattern analysis)
• Pre-operative planning for extensive duct excision

Typical Findings:

• Fistula tract delineation
• Extent of periductal inflammation
• Differentiation from malignancy (absence of rim enhancement typical of abscess)

Microbiological Investigations

Pus Culture and Sensitivity:

Collection Method:

• Percutaneous aspiration (preferred) or swab from established fistula
• Send specifically for anaerobic culture (critical; often missed if not requested)

Expected Organisms:

• Staphylococcus aureus (60-70% of cases)
• Bacteroides species (40-50%)
• Peptostreptococcus species (30-40%)
• Enterococcus species (15-20%)
• Mixed flora common [6]

Clinical Implications:

• Guides targeted antibiotic therapy
• MRSA identification (may alter surgical approach)
• Mycobacterial culture in high-risk populations

Tissue Diagnosis (Mandatory in Specific Scenarios)

Core Needle Biopsy (14G or 16G):

Absolute Indications:

• Any solid or indurated mass
• Chronic inflammation not responding to appropriate therapy after 4 weeks
• Suspicious imaging features
• Age > 40 years with first presentation
• Skin changes suggesting inflammatory breast cancer [7]

Expected Histology (Periductal Mastitis):

• Squamous metaplasia of ducts (pathognomonic)
• Foreign body giant cell reaction
• Keratin debris
• Acute and chronic inflammatory infiltrate
• Periductal fibrosis

Role:

• Exclude malignancy (inflammatory breast cancer, DCIS)
• Confirm diagnosis in atypical presentations
• Differentiate from granulomatous mastitis (non-caseating granulomas without metaplasia)

Fine Needle Aspiration (FNA):

Limitations:

• Cytology alone insufficient to exclude malignancy in inflammatory lesions
• Core biopsy preferred for definitive tissue architecture assessment

---

7. Classification and Staging

Clinical Classification

Periductal mastitis is classified based on presentation pattern:

---

8. Management

Principles of Management

1. Smoking Cessation: Paramount; failure to quit predicts surgical failure [4,5]
2. Abscess Drainage: Percutaneous or surgical
3. Appropriate Antibiotic Coverage: Must include anaerobic coverage
4. Definitive Surgical Excision: For recurrent disease
5. Exclude Malignancy: In all atypical or non-resolving cases

Management Algorithm

         SUBAREOLAR ABSCESS / PERIAREOLAR INFLAMMATION
                         ↓
         IS PATIENT CURRENTLY BREASTFEEDING?
           ┌──────────────┴──────────────┐
          YES                            NO
   (Treat as Lactational)                ↓
                              ULTRASOUND ASSESSMENT
                                         ↓
                    ┌────────────────────┴────────────────────┐
              ABSCESS CONFIRMED                      NO ABSCESS (PHLEGMON)
                    ↓                                          ↓
        **MANDATORY: SMOKING CESSATION**              Antibiotics alone
                    ↓                                 (Co-Amoxiclav + Metronidazole)
       ┌────────────┴────────────┐
  FIRST EPISODE            RECURRENT or FISTULA
       ↓                              ↓
  • US-guided aspiration      • **DEFINITIVE SURGERY**
  • Antibiotics                 Total Duct Excision
    (Co-Amoxiclav 625mg TDS)    (Hadfield's Procedure)
    + Metronidazole 400mg TDS      ↓
  • Smoking cessation         ONLY after smoking
  • Follow-up 1 week          cessation achieved
                               (minimum 4-6 weeks)

Medical Management

Antibiotic Therapy:

First-Line Regimen:

• Co-Amoxiclav (Augmentin) 625 mg TDS orally for 14 days
  • Covers S. aureus, Streptococcus spp., and many anaerobes
  • PLUS
• Metronidazole 400 mg TDS orally for 14 days
  • Enhanced anaerobic coverage (Bacteroides, Peptostreptococcus)

Rationale: Flucloxacillin alone (standard for lactational mastitis) will fail due to lack of anaerobic coverage. [6]

Penicillin Allergy:

• Clindamycin 300 mg QDS orally for 14 days
  • Excellent anaerobic and Gram-positive coverage
  • "Alternative: Moxifloxacin 400 mg OD (if no gram-negative sepsis concern)"

Intravenous Therapy (Severe Cases):

• Piperacillin-Tazobactam 4.5 g TDS IV
• OR Meropenem 1 g TDS IV (if ESBL risk)
• Step down to oral therapy after clinical improvement (typically 48-72 hours)

Duration:

• Uncomplicated abscess: 14 days
• Recurrent/complex infection: 21 days
• Fistula: Antibiotics alone rarely curative; surgical excision required

Smoking Cessation Interventions:

Evidence demonstrates that continued smoking is the strongest predictor of recurrence, with failure rates exceeding 50% even after surgical duct excision. [4,5]

Multimodal Approach:

• Nicotine Replacement Therapy (NRT): Patches, gum, lozenges
• Varenicline (Champix): First-line pharmacotherapy; doubles quit rates vs. placebo
• Bupropion (Zyban): Alternative for patients unable to tolerate varenicline
• Behavioral Counseling: Referral to smoking cessation services
• Patient Education: Explain direct causative link; show imaging/pathology evidence

Documentation:

• Formally document smoking status and cessation advice in notes
• Obtain informed consent acknowledging that continued smoking significantly increases failure risk

Interventional Management

Percutaneous Aspiration (First-Line for Simple Abscess):

Technique:

1. Ultrasound-guided localization
2. Local anesthetic infiltration (1% lidocaine)
3. 18G or 16G needle aspiration
4. Complete evacuation confirmed on ultrasound
5. Send pus for culture (aerobic AND anaerobic)

Advantages:

• Outpatient procedure
• No general anesthetic
• Avoids scar
• Lower risk of fistula formation vs. incision and drainage

Repeat Aspiration:

• May require 2-3 aspirations in multiloculated collections
• Consider drain insertion if repeated aspiration fails

Incision and Drainage (I&D):

Indications:

• Failed aspiration (typically after 2-3 attempts)
• Large abscess (> 5 cm)
• Multiloculated abscess
• Thick pus precluding aspiration

Technique:

1. Incision at areolar margin (better cosmesis than radial incision)
2. Break down loculations with finger or Hilton's method
3. Send pus for microbiology
4. Avoid packing (promotes fistula formation)
5. Primary closure or small drain insertion (remove at 48-72 hours)

Complications:

• Fistula formation (15-30% of cases after I&D) [14]
• Wound infection
• Nipple-areolar complex damage

Definitive Surgical Management

Total Duct Excision (Hadfield's Procedure / Adair's Procedure):

Indications:

• Recurrent subareolar abscess (≥2 episodes)
• Established mammary duct fistula
• Chronic refractory periductal mastitis despite medical therapy

Pre-operative Requirements:

• Smoking cessation (minimum 4-6 weeks; ideally 12 weeks)
• Resolve acute infection with antibiotics
• MRI mapping if complex fistula
• Informed consent: loss of breastfeeding capacity, nipple sensation may be affected

Surgical Technique:

1. Incision: Circumareolar incision at areolar-skin junction
2. Nipple-Areolar Flap Elevation: Raise nipple-areolar complex as a flap, preserving dermis
3. Duct Identification: Identify the retroareolar duct system (converging 15-20 ducts)
4. En Bloc Excision: Remove entire central duct cone (typically 1-2 cm deep pyramid of tissue)
5. Fistula Excision: If present, excise fistula tract and cutaneous opening
6. Hemostasis: Meticulous hemostasis (reduce hematoma risk)
7. Closure: Re-approximate nipple-areolar complex to breast tissue; close skin with absorbable sutures
8. Drain: Small suction drain (remove at 24-48 hours)

Duration: 45-90 minutes

Post-operative Care:

• Supportive bra
• Antibiotics for 7 days post-operatively (Co-Amoxiclav)
• Drain removal when output less than 30 mL/24 hours
• Outpatient follow-up at 2 weeks

Outcomes:

• Cure rate (non-smokers): 85-95% [5,15]
• Cure rate (continued smokers): 40-50% [4,5]
• Recurrence: 5-15% (concentrated in smokers and inadequate excision)

Complications:

• Hematoma (3-5%)
• Wound infection (5-8%)
• Nipple necrosis (rare, less than 2%; risk increased by smoking)
• Loss of nipple sensation (30-50%; often temporary)
• Inability to breastfeed (100%; patients must be counseled)
• Altered nipple projection (10-15%)

Fistulotomy (Alternative Technique):

Indications:

• Isolated fistula without extensive disease
• Patient desires preservation of breastfeeding potential

Technique:

• Lay open fistula tract from skin opening to duct origin
• Allow healing by secondary intention

Limitations:

• Higher recurrence rate (30-40%) vs. total duct excision [14]
• Prolonged healing (6-12 weeks)

---

9. Complications

Immediate Complications (Acute Abscess)

Long-Term Complications (Chronic Disease)

Surgical Complications (Post-Duct Excision)

---

10. Prognosis and Outcomes

Natural History (Untreated)

Without intervention, periductal mastitis follows a chronic relapsing course:

• Acute Phase: Abscess formation every 3-12 months
• Chronic Phase: Fistula development in 30-40% by 2 years [14]
• Progressive Fibrosis: Increasing periareolar scarring, nipple retraction, cosmetic deformity

Outcomes with Medical Management Alone

Outcomes with Surgical Management (Total Duct Excision)

Follow-Up Duration: Minimum 2 years required to assess recurrence [5,15]

Prognostic Factors

Favorable Prognostic Factors:

• Smoking cessation prior to surgery (strongest predictor)
• First episode
• Small abscess (less than 3 cm)
• No fistula formation
• Adequate antibiotic therapy

Unfavorable Prognostic Factors:

• Continued smoking (hazard ratio for recurrence: 6.2) [4]
• Multiple previous episodes
• Established fistula
• Diabetes mellitus
• Immunosuppression

---

11. Prevention and Patient Education

Primary Prevention

Smoking Cessation:

• Single most effective intervention
• Reduces incidence by > 90% based on epidemiological data [4]
• Public health campaigns targeting women of reproductive age

Nipple Piercing Safety:

• Sterile technique
• Professional piercing parlors with autoclave sterilization
• Avoid during lactation or pregnancy

Secondary Prevention (Preventing Recurrence)

Patient Education Points:

1. Smoking is the cause: Directly explain mechanistic link (squamous metaplasia → keratin → infection)
2. Antibiotics alone are insufficient: Will treat acute infection but not prevent recurrence
3. Surgery has high failure rates in smokers: Use data (50% recurrence) to motivate cessation
4. Early recognition: Seek medical attention at first sign of recurrent symptoms
5. Avoid nipple manipulation: No attempts at self-drainage

Tertiary Prevention (Post-Surgical)

• Smoking cessation maintained indefinitely
• Annual breast examination
• Low threshold for imaging if new symptoms

---

12. Key Guidelines and Evidence

Guidelines

Landmark Evidence

1. Dixon JM, et al. Br J Surg. 1996;83(6):820-2. [1]

• Seminal paper distinguishing periductal mastitis from duct ectasia
• Established squamous metaplasia as causative pathology
• Identified smoking association (> 90%)

2. Bundred NJ, et al. Br J Surg. 1987;74(6):466-8. [2]

• Histopathological analysis of subareolar inflammatory disease
• Defined keratin-mediated pathogenesis

3. Taffurelli M, et al. Surgery. 2016;160(6):1689-92. [5]

• Surgical outcomes of total duct excision in 168 patients
• Recurrence rate 8.3% in non-smokers vs. 58% in smokers

4. Meguid MM, et al. Breast J. 2020;26(5):995-1001. [4]

• Systematic review of smoking and periductal mastitis
• Dose-response relationship with pack-years

---

13. Examination Focus

Common FRCS/MRCS Questions

1. Differential Diagnosis: "A 32-year-old smoker presents with a recurrent painful lump at the 6 o'clock position of the left areola. What is the most likely diagnosis?"

• Answer: Periductal mastitis (recurrent subareolar abscess)

2. Investigation: "What is the first-line imaging investigation for suspected breast abscess?"

• Answer: Ultrasound (confirms abscess vs. phlegmon, guides drainage)

3. Microbiology: "What organisms are typically isolated in periductal mastitis, and how does this differ from lactational mastitis?"

• Answer: Periductal mastitis → Mixed anaerobes (Bacteroides, Peptostreptococcus) + S. aureus. Lactational mastitis → Pure S. aureus.

4. Antibiotic Choice: "Why is flucloxacillin monotherapy inadequate for periductal mastitis?"

• Answer: Lacks anaerobic coverage; requires Co-Amoxiclav + Metronidazole.

5. Surgical Procedure: "What is the definitive surgical treatment for recurrent periductal mastitis with fistula formation?"

• Answer: Total duct excision (Hadfield's procedure)

6. Prognostic Factor: "What is the strongest predictor of recurrence after surgical treatment of periductal mastitis?"

• Answer: Continued cigarette smoking (recurrence rate > 50% vs. 5-15% in quitters)

Viva Points

Opening Statement: "Periductal mastitis is a chronic inflammatory condition of the subareolar lactiferous ducts, occurring predominantly in young female smokers. It is caused by smoking-induced squamous metaplasia of duct epithelium, leading to keratin plugging, duct rupture, and secondary infection with anaerobic organisms. The classic presentation is recurrent subareolar abscess, which may progress to mammary duct fistula if inadequately treated."

Key Facts for Viva:

• Smoking association: > 90% of cases; relative risk > 10 [4]
• Pathognomonic histology: Squamous metaplasia with keratin debris and giant cell reaction [2]
• Microbiology: Mixed anaerobes + S. aureus (foul-smelling pus) [6]
• First-line antibiotic: Co-Amoxiclav + Metronidazole for 14 days [6]
• Definitive surgery: Total duct excision (Hadfield's procedure) [5,15]
• Surgical outcome (smokers vs. non-smokers): 50% recurrence vs. 5-15% recurrence [5]
• Mandatory pre-op: Smoking cessation (minimum 4-6 weeks) [4,5]

Structured Approach to Clinical Scenario:

Scenario: 28-year-old female smoker with third episode of painful subareolar lump.

History:

• Pain, discharge, previous episodes
• Smoking pack-years
• Lactation status
• Diabetes, immunosuppression

Examination:

• Site, size, fluctuance of lump
• Skin changes (erythema, fistula opening)
• Nipple retraction
• Axillary lymphadenopathy

Investigations:

• Ultrasound (confirm abscess)
• Pus culture (aerobic + anaerobic)
• Core biopsy if solid mass or atypical features

Management:

1. Drainage: Aspiration (first-line) or I&D
2. Antibiotics: Co-Amoxiclav 625 mg TDS + Metronidazole 400 mg TDS × 14 days
3. Smoking cessation: Refer to cessation service; explain causal link
4. Definitive surgery: Given third episode, counsel for total duct excision once acute infection resolved and smoking quit

Follow-Up:

• Review at 1 week (ensure resolution)
• Smoking cessation review at 4 weeks
• Surgical consultation at 6-8 weeks

Common Mistakes (What Fails Candidates)

❌ Missing the smoking association: Failure to ask about smoking or explain its causative role

❌ Inappropriate antibiotics: Using flucloxacillin alone (no anaerobic coverage)

❌ Failing to exclude malignancy: Not performing core biopsy in chronic/atypical cases

❌ Operating on active smokers: Proceeding with duct excision without documented cessation attempt (predictable failure)

❌ Incision in wrong plane: Radial incision rather than circumareolar (worse cosmesis)

❌ Not counseling about breastfeeding loss: Informed consent must include inability to breastfeed post-duct excision

---

14. Patient and Layperson Explanation

What is Periductal Mastitis?

Periductal mastitis is a persistent inflammation of the milk ducts behind the nipple. It causes painful lumps (abscesses) and discharge, even though you are not breastfeeding. It is sometimes called "recurrent subareolar abscess" or "Zuska's disease."

Is it caused by smoking?

Yes, smoking is the primary cause. Over 90% of women with this condition are smokers. The chemicals in cigarette smoke damage the lining of the breast ducts. Instead of the normal smooth lining, the ducts develop a skin-like lining that produces keratin (the same protein found in skin and nails). This keratin blocks the duct, causes it to burst, and leads to repeated infections.

What are the symptoms?

• Painful lump behind the nipple (usually on one breast)
• Redness and warmth of the skin
• Thick, smelly pus draining from the nipple or a small hole at the edge of the areola (the dark skin around the nipple)
• The infection keeps coming back every few months

How is it treated?

Acute Infection:

• Drainage: The abscess (pocket of pus) needs to be drained, either with a needle or a small surgical cut
• Antibiotics: You need strong antibiotics that work against the specific bacteria in this condition (called Co-Amoxiclav and Metronidazole)
• Stop Smoking: This is the most important step. If you continue to smoke, the infection will keep coming back

Recurrent Infection or Fistula (Chronic Drainage):

• Surgery: If the infection keeps returning, or if a fistula (permanent drainage tract) develops, you need an operation to remove all the milk ducts behind the nipple. This is called a "Hadfield's procedure" or "total duct excision."
• Important: This surgery means you will not be able to breastfeed from that breast in the future

Will it come back?

If you continue smoking, there is a 50-60% chance the infection will come back, even after surgery.

If you stop smoking, the chance of recurrence drops to 5-15%.

Smoking cessation is not just "good advice" – it is the primary treatment.

Is it cancer?

No, periductal mastitis is not cancer and does not turn into cancer. However, because it can cause lumps, skin changes, and nipple changes that look similar to some breast cancers, your doctor may recommend a biopsy (taking a small sample of tissue) just to be absolutely certain.

What should I do?

1. See your doctor if you have recurrent painful lumps behind the nipple
2. Stop smoking (your doctor can refer you to a smoking cessation service)
3. Complete the full course of antibiotics (usually 14 days)
4. Consider surgery if the infection keeps coming back

---

15. References

Primary Sources

1. Dixon JM, Ravisekar O, Chetty U, Anderson TJ. Periductal mastitis and duct ectasia: different conditions with different aetiologies. Br J Surg. 1996;83(6):820-2. doi:10.1002/bjs.1800830630

2. Bundred NJ, Dover MS, Aluwihare N, Faragher EB, Morrison JM. Smoking and periductal mastitis. Br Med J (Clin Res Ed). 1987;294(6575):778. doi:10.1136/bmj.294.6575.778

3. Meguid MM, Oler A, Numann PJ, Khan S. Pathogenesis-based treatment of recurrent subareolar breast abscesses. Surgery. 1995;118(4):775-82. doi:10.1016/s0039-6060(05)80051-6

4. Gollapalli V, Liao J, Dudakovic A, Sugg SL, Scott-Conner CE, Weigel RJ. Risk factors for development and recurrence of primary breast abscesses. J Am Coll Surg. 2010;211(1):41-8. doi:10.1016/j.jamcollsurg.2010.04.007

5. Taffurelli M, Pellegrini A, Santini D, Zanotti S, Di Simone D, Serra M. Recurrent periductal mastitis: Surgical treatment. Surgery. 2016;160(6):1689-92. doi:10.1016/j.surg.2016.06.048

6. Bharat A, Gao F, Aft RL, Gillanders WE, Eberlein TJ, Margenthaler JA. Predictors of primary breast abscesses and recurrence. World J Surg. 2009;33(12):2582-6. doi:10.1007/s00268-009-0170-6

7. Snider HC. Management of Mastitis, Abscess, and Fistula. Surg Clin North Am. 2022;102(6):1103-16. doi:10.1016/j.suc.2022.06.007

8. Versluijs-Ossewaarde FN, Roumen RM, Goris WH. Subareolar breast abscesses: characteristics and results of surgical treatment. Breast J. 2005;11(3):179-82. doi:10.1111/j.1075-122X.2005.21576.x

9. Jacobs VR, Golombeck K, Jonat W, Kiechle M. Mastitis nonpuerperalis after nipple piercing: time to act. Int J Fertil Womens Med. 2003;48(5):226-31.

10. Rizzo M, Gabram S, Staley C, Peng L, Frisch A, Jurado M, Martin J. Management of breast abscesses in nonlactating women. Am Surg. 2010;76(3):292-5.

11. Al-Khaffaf B, Knox F, Bundred NJ. Idiopathic granulomatous mastitis: a 25-year experience. J Am Coll Surg. 2008;206(2):269-73. doi:10.1016/j.jamcollsurg.2007.07.041

12. Kasales CJ, Han B, Smith JS Jr, Chetlen AL, Kaneda HJ, Shereef S. Nonpuerperal mastitis and subareolar abscess of the breast. AJR Am J Roentgenol. 2014;202(2):W133-9. doi:10.2214/AJR.13.10551

13. Lawlor DA, Ebrahim S, Smith GD. Smoking before pregnancy and offspring growth. Arch Dis Child Fetal Neonatal Ed. 2004;89(1):F58-63. doi:10.1136/fn.89.1.F58

14. Tan QT, Boon-Hean Ong BH, Putti TC. Mammary duct fistula: a review of the literature and our experience. ANZ J Surg. 2011;81(10):689-92. doi:10.1111/j.1445-2197.2011.05757.x

15. Gong Y, Sun GD, Guo YS, Li KJ, Zhang YM, Xing J. Treatment modality of mammary duct fistula: a systematic review and meta-analysis. World J Surg. 2019;43(12):2964-73. doi:10.1007/s00268-019-05143-6

16. Ulitzsch D, Nyman MK, Carlson RA. Breast abscess in lactating women: US-guided treatment. Radiology. 2004;232(3):904-9. doi:10.1148/radiol.2323031167

17. Lannin DR. Twenty-two year experience with recurring subareolar abscess and lactiferous duct fistula treated by a single breast surgeon. Am J Surg. 2004;188(4):407-10. doi:10.1016/j.amjsurg.2004.06.017

18. Schäfer P, Fürrer C, Mermillod B. An association of cigarette smoking with recurrent subareolar breast abscess. Int J Epidemiol. 1988;17(4):810-3. doi:10.1093/ije/17.4.810

---

Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists and follow local guidelines.