Side effects of systemic cancer therapy - mucositis
Red flags
- Mucositis + fever in a neutropenic patient -> neutropenic sepsis pathway (mucosal breach is a major bacteraemia entry point)
- Inability to swallow saliva/secretions, stridor -> airway risk, urgent assessment
- Signs of candidal or HSV superinfection on mucositis (white plaques, punched-out ulcers) -> treat concurrently, do not assume all pain is "just mucositis"
- Severe dehydration/inability to maintain oral intake -> IV fluids/nutrition support needed
- Diarrhoea with abdominal pain post-chemotherapy -> GI mucositis with possible neutropenic enterocolitis (typhlitis) if neutropenic
Differential by mechanism
By causative therapy
- Cytotoxic chemotherapy - direct mucosal epithelial damage (5-FU, methotrexate, high-dose melphalan/conditioning regimens particularly severe)
- Radiotherapy (head/neck, pelvic fields) - cumulative, worsens through the treatment course
- Targeted therapy - mTOR inhibitors (everolimus - distinctive aphthous-type stomatitis), EGFR inhibitors
GI mucositis beyond the mouth
- Oesophagitis, enteritis, colitis - same mechanism along the GI tract, presents as odynophagia, diarrhoea, abdominal pain
Mimics/superinfection to distinguish from uncomplicated mucositis
- Oral candidiasis - white plaques, wipeable
- HSV reactivation - punched-out, vesicular-based ulcers, more localised
- Both can coexist with and complicate chemotherapy-induced mucositis
Focused history
- Timing relative to chemotherapy/radiotherapy cycle (typically days 5-10 post-cytotoxic chemotherapy, cumulative through radiotherapy course)
- Specific regimen used (identifies expected severity/risk)
- Pain severity and impact on oral intake/hydration
- Diarrhoea, abdominal pain (GI mucositis)
- Fever (triggers neutropenic sepsis assessment)
- Prior mucositis severity with same regimen (predicts recurrence severity)
Focused examination
- Grade severity (WHO/CTCAE scale) - erythema alone vs ulceration vs inability to eat solid/liquid
- Look specifically for superinfection - white plaques (candida), vesicular/punched-out lesions (HSV)
- Hydration status, weight trend
- Abdominal exam if GI symptoms - distension, tenderness (consider neutropenic enterocolitis if neutropenic with severe pain)
- Vital signs - fever changes management priority immediately
Investigation strategy
- Largely clinical grading; investigate specifically when superinfection or systemic complication suspected
- Oral swab/scraping if candida or HSV suspected and diagnosis unclear
- FBE - concurrent neutropenia changes the urgency and threshold for admission/IV antibiotics
- Stool studies (C. difficile, culture) if diarrhoea with GI mucositis, especially post-antibiotic exposure
- CT abdomen if neutropenic enterocolitis (typhlitis) suspected - fever, right iliac fossa pain, diarrhoea in a neutropenic patient
Management
A. Prevention (built into treatment planning, not an afterthought)
- Oral hygiene protocol before and during treatment - regular saline/bicarbonate mouth rinses, soft toothbrush, dental review before high-risk regimens/head-neck radiotherapy
- Cryotherapy (ice chips) during bolus 5-FU infusion - reduces incidence via local vasoconstriction
- Palifermin (keratinocyte growth factor) - selected high-dose chemotherapy/haematopoietic stem cell transplant settings
B. Established mucositis - symptomatic and staged by severity
- Mild: saline/bicarbonate rinses, avoid irritants (alcohol-based mouthwash, spicy/acidic/rough food), topical analgesics
- Moderate-severe: topical anaesthetics (e.g. lidocaine gel/rinse), systemic analgesia including opioids if severe (odynophagia can be intensely painful - treat proportionately, per Cancer-related pain note)
- Severe with inability to maintain oral intake: IV fluids, nutrition support (nasogastric/parenteral if prolonged), consider treatment delay/dose modification for the next cycle
C. Superinfection - treat specifically, do not just escalate mucositis care
- Oral candidiasis: topical nystatin/miconazole, or oral fluconazole if extensive/oesophageal involvement
- HSV reactivation: aciclovir (oral or IV depending on severity/ability to swallow)
D. GI mucositis
- Supportive - antidiarrhoeals only once infective causes (including C. difficile) excluded, hydration, electrolyte correction
- Neutropenic enterocolitis (typhlitis): broad-spectrum antibiotics as for neutropenic sepsis, bowel rest, surgical review if perforation/necrosis suspected - avoid surgery unless absolutely necessary given coagulopathy/neutropenia risk
E. Dose modification
- Recurrent severe mucositis may prompt dose reduction or regimen change for subsequent cycles - communicate with the treating oncology team
Traps
- Under-treating mucositis pain because it is seen as "expected" rather than assessed and treated on its own merits
- Missing candidal or HSV superinfection and treating everything as uncomplicated chemotherapy mucositis
- Not checking neutrophil count in a febrile mucositis patient - mucosal breach is a major sepsis entry point
- Reaching for antidiarrhoeals in GI mucositis without excluding C. difficile or an infective cause first
- Attempting surgery for neutropenic enterocolitis before exhausting medical management, given the peri-operative risk in a neutropenic, often coagulopathic patient
Talk track
Mucositis follows a predictable timeline after chemotherapy/radiotherapy and is graded by severity, but every case needs an active look for candidal or HSV superinfection rather than assuming uniform cause. Prevention (oral hygiene, cryotherapy for bolus 5-FU) matters as much as treatment. Fever with mucositis always triggers a neutrophil count check, since the mucosal breach is a direct route to bacteraemia - this changes the whole management priority.
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