A 34-year-old male with a 20-year history of epilepsy was treated with valproic acid (500 mg 3 times daily) and phenobarbital (200 mg once daily). As he had frequent convulsive fits, CBZ was added. Thirty-four days later, the patient developed hyperthermia and cervical lymphadenopathy. Initially, he was diagnosed with lymphadenitis and, thus, a therapy of amoxicillin-clavulanic acid (1 g twice daily) and acetaminophen (500 mg 3 times daily), was started. Two days later, a generalized cutaneous eruption (exfoliated and confluent maculae and papulae (Fig. 1) associated with facial angioedema) was also observed. Laboratory findings showed an abnormal white cell count (16.1 × 103/μl, 17% eosinophils), a liver dysfunction with an aspartate aminotransferase level of 50 IU/L (normal 7–38 IU/L) and an alanine aminotransferase level of 116 IU/L (normal 4–40 IU/L), a lactate deshydrogenase level of 3197(normal 190–430 IU/L). The platelet count, INR, the serum levels of immunoglobulins, and the renal function were conversely normal and no atypical lymphocytes were found. The serologic tests for viral infection including cytomegalovirus, Epstein-Barr virus, hepatitis B and C and human immunodeficiency virus were all negative. CBZ, amoxicillin-clavulanic, and acetaminophen were then discontinued and cetirizine (10 mg once daily) was administered. HHV6 serological tests performed on day 21 after the symptoms' onset, with an immunofluorescent antibody assay (Biotrin, Lyon, France), conversely detected anti-HHV6 IgM. About 1 month later, the skin eruption, fever, lymphadenopathy, liver dysfunction, and eosinophilia progressively disappeared. As for his epilepsy, the patient was treated with phenobarbital and valproic acid. Six weeks after complete recovery, prick and patch skin tests to CBZ were performed. CBZ was tested at concentrations of 5% in petrolatum (Romano et al., 2004). The prick test (Stallerpoint, Stallergenes, France) was performed on the volar forearm skin with a 2-day closed patch testing on the back of the patient using Finn Chambers (Finn Chamber, Epitest Ltd Oy, Tuusula, Finland). Histamine and codeine sulfate were used as a positive control for the prick test. Two healthy controls underwent prick and patch tests to CBZ according to the same procedure applied on the patient. Twenty minutes after performing these tests, we only noticed a positive reaction to histamine and codeine sulfate (prick tests to CBZ in the patient and the controls were all negative). Both prick and patch tests were strongly positive at 48-h reading (Figs. 2 and 3, respectively) and no systemic reactions were noticed after these tests. They were negative in healthy controls. Reactions due to skin tests progressively regressed with a complete resolution 1 week later.