What are the causes and treatment options for an 8-year-old male presenting with blisters on the tongue?

Causes of Tongue Blisters in an 8-Year-Old Male

The most common causes of tongue blisters in an 8-year-old include viral infections (particularly herpes simplex virus and hand-foot-mouth disease), traumatic injury, aphthous ulcers, and less commonly, serious conditions like Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), Mycoplasma pneumoniae-induced rash and mucositis (MIRM), or autoimmune blistering diseases.

Primary Differential Diagnosis

Common Benign Causes

• Viral infections are the leading cause in this age group, particularly herpes simplex virus (HSV) and coxsackievirus (hand-foot-mouth disease) 1
• Traumatic blisters from accidental biting, hot foods, or friction during eating are extremely common and self-limiting 2, 3
• Aphthous ulcers (canker sores) present as painful erosions after blister rupture and are recurrent in many children 4
• Angina bullosa hemorrhagica causes sudden hemorrhagic blisters on the tongue, palate, or buccal mucosa, typically from minor trauma, and resolves within 7-10 days without treatment 2, 3, 5

Serious Conditions Requiring Urgent Evaluation

• Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) presents with painful oral blisters, mucosal erosions, and typically involves skin lesions, fever, and systemic symptoms 1, 6
• Mycoplasma pneumoniae-induced rash and mucositis (MIRM) causes severe oral mucositis with blisters, often with mild respiratory symptoms and conjunctivitis 7
• Autoimmune blistering diseases (pemphigus, pemphigoid) are rare in children but cause persistent, recurrent blisters 6
• Epidermolysis bullosa presents with blistering from minimal trauma, typically diagnosed in infancy but milder forms may present later 1

Immediate Assessment Approach

Clinical Red Flags Requiring Urgent Evaluation

• Rapidly progressing lesions within 24 hours suggest SJS/TEN or severe infection 6
• Involvement of multiple mucosal sites (eyes, genitals, lips) indicates SJS/TEN or MIRM 1, 7
• Systemic symptoms including fever, malaise, respiratory symptoms, or skin rash beyond the oral cavity 6, 7
• Body surface area involvement >10% requires immediate hospitalization 6
• Recent medication exposure (antibiotics, anticonvulsants, NSAIDs) raises concern for drug-induced SJS/TEN 1

Essential Initial Evaluation

• Document percentage of oral mucosa involved and photograph lesions to monitor progression 6
• Examine all skin surfaces and other mucous membranes (conjunctiva, genitals) to identify systemic involvement 6
• Take viral swabs from eroded areas if HSV infection is suspected 1
• Obtain bacterial cultures if signs of secondary infection are present (purulent discharge, surrounding erythema, fever) 1, 6
• Arrange urgent ophthalmology review if any eye symptoms or conjunctival involvement is present 1

Management Based on Severity

For Isolated Tongue Blisters Without Systemic Symptoms

• Leave intact blisters alone as the blister roof acts as a natural biological dressing 1, 6, 8
• If drainage is necessary, pierce the blister at its base with a sterile needle and apply gentle pressure with sterile gauze, but leave the roof intact 1, 6, 8
• Clean the mouth daily with warm saline mouthwashes or an oral sponge 1
• Apply white soft paraffin ointment to affected areas every 2 hours to support barrier function and reduce pain 1
• Use benzydamine hydrochloride oral rinse or spray every 2-4 hours, particularly before eating, to reduce inflammation and pain 1
• Administer pain relief 20 minutes before meals (acetaminophen or ibuprofen) to facilitate eating 1

For Extensive Oral Involvement (>10% of oral mucosa)

• Consider potent topical corticosteroid mouthwash such as betamethasone sodium phosphate four times daily 1
• Consult dermatology for evaluation of potential systemic disease 6
• Monitor for signs of dehydration and consider intravenous hydration if oral intake is severely compromised 1

For Suspected SJS/TEN or MIRM

• Immediate hospitalization under dermatology or multidisciplinary team supervision is mandatory 6
• Discontinue all potentially causative medications immediately 6
• Instigate daily oral review during the acute phase 1
• Provide adequate analgesia using intravenous opioid infusions if not tolerating oral medication 1
• Monitor closely for signs of sepsis with urgent intervention if suspected 1

Prevention of Complications

Infection Prevention

• Monitor daily for signs of infection including increased pain, purulent discharge, fever, or surrounding erythema 1, 6
• Take bacterial and viral cultures from erosions with clinical signs of infection before initiating antibiotics 1, 6
• Apply topical antimicrobials (silver-based products) only to areas with clinical signs of infection, not prophylactically, and for short periods only 6, 8, 9

Nutritional Support

• Offer favorite drinks for oral irrigation rather than standard mouthwashes to encourage compliance 1
• Provide soft, cool foods and avoid acidic or spicy items that may irritate lesions 1
• Consider nutritional supplementation if oral intake is significantly reduced for more than 48 hours 1

Critical Pitfalls to Avoid

• Do not assume simple trauma if lesions progress rapidly within 24 hours or involve multiple sites 6
• Do not routinely de-roof blisters as the roof provides protective biological coverage 1, 6, 8, 9
• Do not apply topical antimicrobials prophylactically to all blisters; reserve for clinically infected areas only 6, 8, 9
• Do not delay ophthalmology evaluation if there is any mucosal involvement beyond the oral cavity 1
• Do not delay skin biopsy if the diagnosis is unclear or lesions are persistent, as this is essential for definitive diagnosis 6
• Do not overlook the need for viral swabs if HSV is suspected, as early antiviral therapy may be beneficial 1