Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, neoplastic or neurological disorders and drug reactions. To our knowledge, this is the first case of cenobamate as a cause of neutrophilic dermatoses which was misdiagnosed as neuro-sweet syndrome (NSS).

A 34-year-old female presented with complex partial seizures treated initially with carbamazepine and levetiracetam which were discontinued due to dysarthria, and psychiatric symptoms.  Therefore, lacosamide and topiramate were switched but doses were decreased due to visual auras and distortions of perception. Finally, cenobamate was included in her regimen. A painless rash on her left arm developed after 1 week of its addition. Over the course of three weeks, the rash progressed and increased in size, with an additional lesion appearing on her right arm. Consequently, the Dermatologist performed a punch biopsy of the rash which revealed numerous neutrophils scattered throughout the dermis and evidence of leukocytoclasia, suspecting sweet syndrome in the histopathological analysis. Three weeks after discontinuing the medication and a week after receiving the glucocorticoid injection, the patient's rash transitioned from a plaque to a macule and ceased to progress. After 8 weeks it disappeared completely. The seizures were controlled with an increased dose of lacosamide and the same topiramate dose.