Anticonvulsant hypersensitivity syndrome

[3][4] Systemic manifestations occur at the time of skin manifestations and include a high number of eosinophils in the blood, liver inflammation, and interstitial nephritis.

However, a subgroup of patients may become hypothyroid as part of an autoimmune thyroiditis up to 2 months after the initiation of symptoms.

The risk of first-degree relatives developing the same hypersensitivity reaction is higher than in the general population.

"[2]: 118  As of 2015, two cases of AHS have been reported that manifested during long-term treatment with multiple anti-seizure medications.

Death due to multiple organ failure can occur; symptoms also mimic lymphoma and AHS has been called "pseudolymphoma" as a result.