What is the cause and treatment of a red and swollen tongue in a patient with an unknown medical history and age?

Red and Swollen Tongue: Differential Diagnosis and Management

A red and swollen tongue requires immediate assessment for life-threatening angioedema (especially if recent thrombolytic therapy or ACE inhibitor use), followed by systematic evaluation for infectious causes (candidiasis, scarlet fever), pediatric emergencies (Kawasaki disease), and nutritional deficiencies (vitamin B12, folate, iron).

Immediate Life-Threatening Considerations

Orolingual Angioedema

• Post-thrombolytic angioedema occurs in 1.3-5.1% of patients receiving intravenous thrombolysis and can be unilateral (typically contralateral to affected hemisphere) or bilateral 1
• Risk increases with concurrent ACE inhibitor use and frontal/insular strokes 1
• Immediate treatment includes corticosteroids, antihistamines, and preparation for possible intubation 1
• Hereditary angioedema with plasminogen variant (HAE-PLG) frequently causes tongue swelling and has resulted in death from asphyxiation 1

Drug-Induced Reactions

• Oseltamivir (Tamiflu) can rarely cause tongue swelling, resolving rapidly with antihistamines and drug discontinuation 2
• Always obtain medication history including recent initiation of ACE inhibitors, thrombolytics, or antivirals 1, 2

Infectious Causes Requiring Urgent Treatment

Candidiasis (Oral Thrush)

• Presents with bright red tongue after white plaques are removed, particularly in immunocompromised patients 3
• Diagnosis confirmed by scraping and KOH preparation microscopy 3
• Treatment requires topical or systemic antifungal therapy 1, 3

Scarlet Fever (Group A Streptococcal Infection)

• "Strawberry tongue" appears initially white-coated, then bright red with prominent papillae 3
• Accompanied by fever, sore throat, characteristic sandpaper-like rash, and tender anterior cervical lymphadenopathy 4
• Most common in children aged 5-15 years 4
• Requires immediate antibiotic therapy to prevent acute rheumatic fever 3, 5
• Critical pitfall: At least one-third of acute rheumatic fever cases result from inapparent streptococcal infections 5

Pediatric Emergency: Kawasaki Disease

Clinical Recognition

• Red, swollen "strawberry tongue" in a child with fever >102.2°F (39°C) for ≥5 days is Kawasaki disease until proven otherwise 1, 3
• Associated findings include bilateral non-purulent conjunctival injection, cervical lymphadenopathy ≥1.5 cm, polymorphous rash, and swelling/erythema of hands and feet 1
• Diagnosis can be made with fever <5 days if typical features plus coronary artery findings on echocardiography are present 1

Urgent Management Algorithm

• If fever >5 days with 2-3 classic symptoms: measure CRP and ESR immediately 1
• If elevated, obtain serum albumin, transaminase levels, CBC, and urinalysis 1
• First-line treatment: IVIG 2 g/kg single infusion PLUS high-dose aspirin 80-100 mg/kg/day divided into four doses 1
• Perform echocardiography immediately to assess for coronary artery abnormalities 1
• Untreated Kawasaki disease leads to serious cardiac complications including coronary artery aneurysms 1, 3

Nutritional Deficiencies

Atrophic Glossitis

• "Beefy red, smooth tongue" indicates atrophic glossitis from nutritional deficiency 3, 6
• Most commonly caused by deficiencies of iron, folic acid, vitamin B12, riboflavin, or niacin 3, 7
• Vitamin B12 deficiency presents with macrocytosis on CBC and low serum B12 levels 6

Diagnostic Approach

• Obtain hematologic screening: CBC, red-cell indices, serum iron, B12, and folate levels 8
• Tongue swelling with papillary atrophy and surface ulceration possible in most deficiency states 8
• Multiple nutritional deficiencies commonly coexist, complicating clinical diagnosis 8
• Treatment: replacement therapy resolves symptoms and prevents irreversible systemic and neurologic damage 8, 6

Inflammatory and Systemic Conditions

Burning Mouth Syndrome

• Burning sensation with normal-appearing or bright red tongue 1, 3
• Predominantly affects peri- and post-menopausal women 1, 3
• Associated with dry mouth, abnormal taste, and depression 1, 3
• Treatment includes reassurance, cognitive behavioral therapy, and possibly neuropathic pain medications 1

Vasculitis and Thyroid Disorders

• Vasculitis can present with bright red tongue, often involving multiple organ systems 3
• Hyperthyroidism may cause tongue erythema with other thyroid dysfunction symptoms 3

Critical Diagnostic Pitfalls to Avoid

• Never diagnose specific nutritional deficiency on clinical impression alone—always obtain laboratory confirmation 8
• Group C and G streptococcal pharyngitis present identically to Group A strep but do NOT cause acute rheumatic fever 5
• Approximately 15% of school-age children are asymptomatic GAS carriers, making throat culture interpretation challenging 5
• In suspected Kawasaki disease, do not delay treatment waiting for all diagnostic criteria—incomplete presentation still requires urgent management 1
• Post-thrombolytic angioedema may be unilateral and contralateral to stroke hemisphere, potentially causing diagnostic confusion 1

Systematic Evaluation Algorithm

1. Assess airway patency immediately—prepare for intubation if tongue swelling compromises breathing 1
2. Obtain medication history—recent thrombolytics, ACE inhibitors, antivirals 1, 2
3. Check vital signs and fever duration—fever ≥5 days in children mandates Kawasaki disease evaluation 1
4. Examine for associated findings: rash, lymphadenopathy, conjunctivitis, extremity changes 1, 4
5. Obtain targeted laboratory studies: CBC with indices, B12, folate, iron, CRP/ESR (if pediatric with fever), throat culture/rapid strep test 1, 4, 8
6. Perform oral examination: scrape white plaques if present for KOH prep 3
7. Initiate treatment based on most likely diagnosis while awaiting confirmatory results 1, 3