A Woman with a Rash and Rising Creatinine
A 47-year-old woman presents with a 2-week history of a painful, dusky erythematous rash on the face, neck and upper chest, with targetoid lesions on the forearms and oral erosions. She has been taking lamotrigine for 6 weeks, started at 25 mg daily and increased to 50 mg daily 2 weeks ago. She is febrile at 38.6°C, has a heart rate of 118/min and blood pressure of 92/58 mmHg. Mucous membranes show haemorrhagic crusting of the lips and conjunctival injection. Laboratory results: creatinine 210 µmol/L (baseline 70), ALT 180 U/L, eosinophils 1.4 × 10⁹/L, and a CRP of 120 mg/L.
1. What is the diagnosis and what immediate actions are required?
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Diagnosis: drug reaction with eosinophilia and systemic symptoms (DRESS) related to lamotrigine, with mucosal involvement raising overlap with Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). The combination of a new aromatic anticonvulsant, fever, facial/upper trunk rash, eosinophilia, hepatitis and acute kidney injury fits DRESS; mucosal erosions and targetoid lesions raise SJS/TEN overlap. Both are life-threatening.
Immediate actions:
- Stop lamotrigine immediately - the single most important step.
- Admit to a high-dependency or burns/ICU setting with fluid resuscitation and haemodynamic support for hypotension.
- Calculate the SCORTEN if SJS/TEN is suspected and document body surface area of epidermal detachment.
- Baseline and serial investigations: FBC, U&E, LFTs, coagulation, urinalysis, blood and skin cultures, and skin biopsy for histology and direct immunofluorescence (to exclude autoimmune blistering).
- Multidisciplinary care: dermatology, intensive care, nephrology, ophthalmology and, if mucosal disease is significant, gynaecology/urology for mucosal assessment.
- Avoid all aromatic anticonvulsants (phenytoin, carbamazepine, phenobarbital, oxcarbazepine) - cross-reactivity is common.
2. How would you treat her, and what specific issues must you address in DRESS versus SJS/TEN?
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General measures: stop the culprit drug; supportive care with fluids, analgesia, wound care and nutritional support; monitor renal and hepatic function closely; ophthalmology review for ocular surface disease.
DRESS-specific:
- Systemic corticosteroids (e.g. prednisolone 1 mg/kg/day, tapering over weeks) are the mainstay; slow taper to avoid relapse.
- Monitor for myocarditis, pneumonitis, thyroiditis and other visceral involvement - check ECG, troponin, thyroid function, and urinalysis.
- Watch for reactivation of HHV-6 and other herpesviruses, which can drive flares; consider PCR if fever recurs.
- Consider IVIG or other immunomodulation in refractory or organ-threatening disease.
SJS/TEN-specific (if overlap confirmed):
- Early withdrawal of the culprit drug and transfer to a burns unit.
- Aggressive fluid and electrolyte management, temperature control, and wound care; avoid adhesive dressings.
- Cyclosporine or etanercept are used as immunomodulators in early SJS/TEN; IVIG is used in some centres but evidence is debated.
- Ocular prophylaxis with lubricants and topical steroids; early amniotic membrane grafting if severe.
Follow-up: document the drug reaction, provide an allergy alert card, and counsel her to avoid lamotrigine and related aromatic anticonvulsants lifelong.