What are the differential diagnoses for painful gingival swelling in a 6‑year‑old boy?

Differential Diagnoses for Painful Gum Swelling in a 6-Year-Old Boy

The most likely diagnosis in a 6-year-old with painful gum swelling is plaque-induced gingivitis or a dental abscess from pulpal infection, and you must immediately examine for dental caries, tooth mobility, visible decay, and signs of periapical infection. 1

Primary Differential Diagnoses

Dental and Periodontal Causes (Most Common)

Plaque-Induced Gingivitis

• The host response to dental plaque biofilm causes gingival inflammation and enlargement, which is the most common periodontal condition in children 1
• Look for red, swollen, bleeding gums adjacent to teeth with visible plaque accumulation 2, 3
• In 6-year-olds, the mixed dentition phase (ages 6-12) creates high risk for dental disease due to difficulty cleaning erupting teeth 4
• Children have lower prevalence and severity of gingivitis than adults, but it remains the predominant periodontal disease in this age group 5

Periapical Abscess from Dental Caries

• Swelling of periapical tissues in primary or permanent dentition justifies intraoral X-ray examination using a dedicated film holder and beam aiming device 1
• Examine systematically for missing teeth, tooth mobility, altered tooth position, gum bleeding, and visible tooth fractures 6
• A fistula in the vestibular mucosa near the tooth apex indicates septic pulpal lesion affecting periapical tissues 1
• Extensive gingival swelling, multiple teeth moving together when palpated, or tooth displacement interfering with occlusion requires immediate dental referral 6

Periodontal Abscess

• This represents a relatively frequent dental emergency that can compromise periodontal prognosis 7
• Presents with localized gum swelling, pain, and potential tooth mobility 7
• While less common in children than adults, it can occur in pre-existing periodontal pockets or affect previously healthy sites 7

Acute Infectious Causes

Necrotizing Periodontal Disease

• Three typical clinical features: papilla necrosis, gingival bleeding, and pain 7
• Represents the most severe condition associated with dental biofilm, with very rapid tissue destruction 7
• Predisposing factors include immunosuppression, malnutrition, stress, or tobacco exposure (less likely in a 6-year-old) 7
• Although prevalence is not high, the severity and rapid progression make this diagnosis critical to exclude 7

Non-Plaque-Induced Gingival Infections

• Viral infections (herpes simplex, herpes zoster) present with painful oral lesions and gingival involvement 1
• Bacterial infections beyond typical oral flora can cause acute gingival swelling 2
• These conditions may prompt emergency dental visits despite typically not being severe 7

Trauma-Related Causes

Dental Trauma with Secondary Infection

• Gray tooth discoloration, gingival swelling near affected tooth, or parulis indicates pulpal necrosis after trauma 6
• Luxation injuries can lead to delayed complications including gingival swelling 6
• Consider child abuse in any child younger than 5 years with trauma affecting gingiva, especially with severe tooth injury 6

Systemic Disease Manifestations

Periodontal Manifestations of Systemic Conditions

• Pre-pubertal patients with clear signs of periodontal disease require in-depth medical investigation 1
• Genetic, hematological, immunosuppressive disorders can have periodontal manifestations 3
• Some systemic diseases predispose children to periodontal disease, and family history of periodontitis is important 5, 8
• Children with overt gingival inflammation or early signs of alveolar bone loss should be considered periodontitis-risk patients 5

Less Common Causes

Mucocutaneous Disorders

• Lichen planus, recurrent oral ulceration can cause painful gingival lesions 1
• These typically present with visible mucosal lesions in addition to gingival swelling 7

Allergic or Traumatic Lesions

• Can present as erythematous or erosive gingival lesions 7
• May result from direct trauma or breaking of vesicles and bullae 7

Diagnostic Approach

Immediate Clinical Examination

• Examine teeth for obvious decay, mobile teeth, excessive wear facets, and occlusion 1
• Inspect oral mucosa for soft tissue lesions, color changes, and ulcerations 1
• Palpate for tenderness, swelling extent, and fluctuance 1
• Check for fistula formation—if present, take intraoral radiograph with gutta-percha cone inserted inside the fistula 1

Radiographic Evaluation

• Bitewing radiograph is the technique of choice when carious lesions are suspected 1
• Add periapical X-ray if suspect infection involving pulp or apex 1
• CBCT is NOT indicated in the initial diagnostic phase for gingival swelling 1

Red Flags Requiring Immediate Referral

• Extensive gingival or facial swelling 6
• Multiple teeth moving together when palpated 6
• Visible pulp exposure in fractured tooth 6
• Signs suggesting necrotizing disease (papilla necrosis, severe pain, rapid progression) 7

Common Pitfalls

• Do not assume all gingival swelling is simple gingivitis—always examine for underlying dental pathology including caries and periapical infection 1
• Do not order CBCT as first-line imaging—intraoral radiographs with proper technique are sufficient for initial evaluation 1
• Do not miss systemic disease indicators—children with severe periodontal disease may have underlying systemic conditions requiring medical workup 1, 5
• Do not overlook trauma history—delayed complications from dental trauma can present as gingival swelling weeks after injury 6