Can oxcarbazepine (anticonvulsant medication) cause inflammatory dermatitis?

Can Oxcarbazepine Cause Inflammatory Dermatitis?

Yes, oxcarbazepine can definitively cause inflammatory dermatitis and serious dermatological reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), DRESS syndrome, and various forms of cutaneous eruptions. 1

Serious Dermatological Reactions

The FDA label explicitly warns that serious dermatological reactions, including SJS and TEN, have been reported in both children and adults treated with oxcarbazepine. 1 These reactions can be life-threatening and have resulted in rare fatal outcomes, with a median onset of 19 days after treatment initiation. 1

• The reporting rate of TEN and SJS with oxcarbazepine exceeds background incidence rates by 3- to 10-fold. 1
• If a patient develops any skin reaction while taking oxcarbazepine, strong consideration should be given to discontinuing the medication immediately. 1

Genetic Risk Factors

Patients carrying the HLA-B*1502 allele are at significantly increased risk for SJS/TEN with oxcarbazepine treatment. 1 This is particularly relevant because:

• The HLA-B*1502 allele frequency ranges from 2-12% in Han Chinese populations, approximately 8% in Thai populations, and above 15% in the Philippines and some Malaysian populations. 1
• Testing for HLA-B*1502 should be considered in patients with ancestry in genetically at-risk populations prior to initiating oxcarbazepine. 1
• The use of oxcarbazepine should be avoided in HLA-B*1502 positive patients unless benefits clearly outweigh risks. 1

Types of Cutaneous Reactions Documented

Multiple forms of inflammatory dermatitis have been reported with oxcarbazepine:

• Morbilliform rash: Diffuse eruptions with erythema and papules/pustules have been documented, appearing as early as 1 week after initiation. 2
• DRESS syndrome: Drug Reaction with Eosinophilia and Systemic Symptoms, characterized by fever, skin eruption, hematological abnormalities, and internal organ involvement. 3, 4
• Exfoliative dermatitis: DRESS syndrome presenting as exfoliative dermatitis has been reported after 3 weeks of oxcarbazepine therapy. 3
• Cross-reactive eruptions: Patients with previous hypersensitivity to carbamazepine have a 25-30% risk of experiencing similar reactions with oxcarbazepine. 1, 5

Clinical Management Algorithm

When a patient develops dermatitis on oxcarbazepine:

1. Immediately discontinue oxcarbazepine if any skin reaction develops, particularly if accompanied by fever, lymphadenopathy, or systemic symptoms. 1
2. Do not rechallenge patients who have developed serious skin reactions, as recurrence has been documented. 1
3. Initiate supportive therapy: Oral corticosteroids tapered over 2 weeks may be necessary for resolution, as antihistamines and topical corticosteroids alone may be insufficient. 2
4. Monitor for systemic involvement: Check for fever, organ dysfunction, and hematological abnormalities suggestive of DRESS syndrome. 3, 4

Important Caveats

• Cross-reactivity with carbamazepine: Approximately 25-30% of patients with carbamazepine hypersensitivity will react to oxcarbazepine. 1, 5 Patients should be specifically questioned about prior carbamazepine reactions before prescribing oxcarbazepine. 1
• Delayed recognition: The correlation between rash and oxcarbazepine may not be immediately recognized, leading to continued exposure and worsening reactions. 2
• Ethnic considerations: While genetic testing may not always be available, clinicians should maintain heightened vigilance for cutaneous reactions across all populations, particularly those with ancestry from high-risk regions. 2

The evidence from FDA labeling, case reports, and clinical studies consistently demonstrates that oxcarbazepine is a well-established cause of inflammatory dermatitis ranging from mild morbilliform eruptions to life-threatening severe cutaneous adverse reactions. 1, 2, 3, 4