A New Mother's Medical Mystery: Understanding Postpartum Sweet's Syndrome

Table of Contents

• Background: Why This Case Matters
• Case Presentation: The Patient's Story
• Diagnostic Process: How Doctors Investigated
• Key Findings: What Tests Revealed
• Differential Diagnosis: Other Conditions Considered
• Final Diagnosis: Sweet's Syndrome
• Treatment and Outcome
• Clinical Implications for Patients
• Limitations of This Case Study
• Recommendations for Patients
• Source Information

Background: Why This Case Matters

This case illustrates how inflammatory conditions can sometimes mimic infections after childbirth. Sweet's syndrome (acute febrile neutrophilic dermatosis) is a rare inflammatory disorder that can develop during pregnancy or postpartum periods. The condition causes fever, skin lesions, and internal inflammation that can be mistaken for infections, leading to delayed diagnosis and inappropriate antibiotic treatment.

For patients with autoimmune or inflammatory conditions, pregnancy and postpartum periods can trigger disease flares. This case highlights the importance of considering inflammatory conditions when infections don't respond to appropriate treatment, especially in patients with personal or family histories of autoimmune diseases.

Case Presentation: The Patient's Story

A 30-year-old woman was admitted to the hospital six days after delivering her first baby due to fever and abdominal pain. She had received routine prenatal care and delivered a male infant weighing 3575 grams (7 pounds, 14 ounces) at 35 weeks and 3 days of pregnancy, which is considered preterm delivery.

During her pregnancy, she had developed small, painful bumps in her groin area that intermittently drained blood and pus. She also experienced leg swelling that improved after delivery. Her medical history included rosacea, acne, hidradenitis suppurativa (a chronic skin condition causing abscesses and scarring), and previous episodes of diverticulitis (inflammation of small pouches in the colon).

On admission to the hospital, her temperature was 38.7°C (101.7°F), and she had tender, erythematous pustules in her right groin area with scarring on the left side. Her white blood cell count was significantly elevated at 22,940 per microliter (normal range: 4,500-11,000), indicating significant inflammation or infection.

Diagnostic Process: How Doctors Investigated

Doctors initially suspected endometritis (uterine infection) and started treatment with multiple antibiotics including gentamicin, clindamycin, vancomycin, cefepime, and metronidazole. Despite this broad-spectrum antibiotic coverage, her fever, abdominal pain, and leukocytosis (high white blood cell count) did not improve.

Multiple imaging studies were performed:

• Computed tomography (CT) scans showed mild ascites (fluid in abdomen) and anasarca (generalized body swelling)
• Magnetic resonance imaging (MRI) revealed fluid collections in the pelvis measuring 6.3 cm and 3.2 cm
• Later scans showed new liver abnormalities with multiple fluid collections

Doctors performed an endometrial biopsy that showed neutrophilic debris and dense neutrophilic infiltrate. A percutaneous catheter drained 20 ml of purulent fluid from one pelvic collection, but cultures showed no bacterial growth.

On hospital day 11, her condition worsened with increased abdominal pain, shortness of breath, and oxygen saturation dropping to 86% on room air (normal is 95-100%). She required supplemental oxygen at 2 liters per minute.

Key Findings: What Tests Revealed

Laboratory tests showed progressive abnormalities:

• White blood cell count increased from 22,940 to 34,720 per microliter
• Neutrophils (inflammatory cells) increased from 19,230 to 33,470 per microliter
• Hemoglobin dropped from 8.5 to 8.1 g/dL (indicating anemia)
• Platelets increased from 456,000 to 590,000 per microliter
• C-reactive protein (inflammatory marker) was markedly elevated at 132.0 mg/dL (normal: 0.0-0.8)
• Erythrocyte sedimentation rate (another inflammatory marker) was elevated at 55 mm/hr (normal: 0-20)

New skin lesions developed at sites of minor trauma including IV catheter sites and the drainage catheter insertion site. These lesions appeared as violaceous (purplish), friable plaques that ulcerated. This phenomenon where lesions develop at sites of minor trauma is called pathergy.

Imaging studies showed progressive abnormalities including:

• Increasing ascites and anasarca
• New splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver)
• Multiple new intrahepatic fluid collections
• Evidence of possible right heart strain with dilated right heart chambers

Differential Diagnosis: Other Conditions Considered

Doctors considered multiple possible diagnoses before reaching the final conclusion:

Infections: Despite negative cultures, doctors considered atypical infections including fungal and mycobacterial infections, though the patient had no known immune compromise.

Autoinflammatory syndromes: Conditions like PAPA syndrome (pyogenic arthritis, pyoderma gangrenosum, and acne) and PASH syndrome (pyoderma gangrenosum, acne, and hidradenitis suppurativa) were considered due to her skin history and family history of autoimmune conditions.

Systemic vasculitis: The presence of microscopic hematuria, elevated inflammatory markers, and pulmonary symptoms suggested possible vasculitis (blood vessel inflammation), but skin lesions weren't typical for this.

Neutrophilic dermatoses: The pathergy phenomenon (lesions at trauma sites) narrowed the diagnosis to conditions like pyoderma gangrenosum, cutaneous Crohn's disease, Behçet's disease, or Sweet's syndrome.

Final Diagnosis: Sweet's Syndrome

The diagnosis was confirmed by a skin biopsy of an ulcer on her left upper arm. The biopsy showed:

• A dense inflammatory infiltrate throughout the tissue
• Epidermal ulceration and erosion
• A dermal inflammatory infiltrate composed almost exclusively of neutrophils
• No evidence of vasculitis (blood vessel inflammation)
• Negative special staining for microorganisms (bacteria, fungi, and acid-fast bacilli)
• Negative tissue cultures

These findings were consistent with Sweet's syndrome (acute febrile neutrophilic dermatosis), a condition characterized by fever, neutrophilia (high neutrophil count), and painful skin lesions that typically respond to corticosteroids rather than antibiotics.

Treatment and Outcome

Once diagnosed with Sweet's syndrome, the patient was treated with glucocorticoids (anti-inflammatory medications). Her response was dramatic and rapid:

On day 2 of glucocorticoid treatment, the skin ulcer changed from an edematous ulcer with a violaceous border to a shallow, well-demarcated ulcer with greatly diminished inflammation.

By day 3, the lesion showed early marginal reepithelialization (healing from the edges).

After 24 days of treatment, the lesion had nearly complete reepithelialization with only a small area of central hypergranulation.

Two months after completing glucocorticoid treatment, the lesion had healed completely, leaving only a pink patch with a central linear plaque consistent with a hypertrophic scar.

The patient's systemic symptoms also resolved with anti-inflammatory treatment, confirming that the abdominal pain, fever, and internal organ inflammation were all part of the Sweet's syndrome presentation.

Clinical Implications for Patients

This case has several important implications for patients:

Sweet's syndrome can develop during pregnancy or postpartum periods and may be triggered by hormonal changes. Patients with pre-existing inflammatory skin conditions like hidradenitis suppurativa may be at increased risk.

The condition can present with systemic symptoms including fever, abdominal pain, and internal organ inflammation that mimic infections. This can lead to misdiagnosis and unnecessary antibiotic treatment.

The pathergy phenomenon (development of lesions at sites of minor trauma) is an important clue that suggests neutrophilic dermatoses like Sweet's syndrome rather than infection.

Patients with personal or family histories of autoimmune or inflammatory conditions should be aware that pregnancy and postpartum periods might trigger disease flares that require different treatment approaches than infections.

Limitations of This Case Study

This report describes a single patient's experience, which means the findings cannot be generalized to all patients. Sweet's syndrome is rare, affecting approximately 1-3 per million people annually, and its presentation during pregnancy/postpartum is even rarer.

The diagnosis was made after multiple treatments had been attempted, which might have influenced the clinical presentation. The patient's personal history of hidradenitis suppurativa and family history of autoimmune diseases might represent unique risk factors not present in all patients.

No genetic testing was performed for autoinflammatory syndromes like PAPA or PASH syndrome, so we cannot completely rule out these related conditions.

Recommendations for Patients

Based on this case, patients should:

1. Share complete medical histories with healthcare providers, including family history of autoimmune diseases and personal history of inflammatory conditions
2. Be aware that not all fevers after delivery are infections - inflammatory conditions can cause similar symptoms
3. Note any skin changes, especially lesions that develop at sites of minor trauma like IV sites or scratches
4. Ask about diagnostic possibilities if infections aren't responding to appropriate antibiotics
5. Understand that skin biopsies are sometimes necessary to diagnose inflammatory skin conditions

For patients with known inflammatory conditions, discuss pregnancy and postpartum management plans with specialists before delivery. Early recognition of disease flares can prevent unnecessary treatments and complications.

Source Information

Original Article Title: Case 22-2024: A 30-Year-Old Woman with Postpartum Fever, Abdominal Pain, and Skin Ulcers

Authors: Joseph F. Merola, Rory L. Cochran, Daniela Kroshinsky, Malavika Prabhu, Melanie C. Kwan

Publication: The New England Journal of Medicine, July 18, 2024

DOI: 10.1056/NEJMcpc2309500

This patient-friendly article is based on peer-reviewed research from the Case Records of the Massachusetts General Hospital.