A patch test confirmed phenobarbital-induced fixed drug eruption in a child.

A-10-year-old girl was referred to our department for multiple hyperpigmented plaques. One week previously, she had been given one suppository of acetylsalicylic acid - phenobarbital for fever. Twelve hours after the drug intake the child developed pruritic red plaques on the left thigh. Six weeks after resolution of the acute reaction, patch tests were performed separately, with phenobarbital and acetylsalicylic acid. On 48-hour reading, only the phenobarbital patch test on residual pigmented lesion was positive. Because of possible cross-reactions between aromatic anticonvulsants, subsequent patch tests using carbamazepine and phenytoin on residual pigmented lesions were performed. They were all negative at 48-hour reading. To our knowledge, only two isolated pediatric cases of Phenobarbital-induced FDE have been reported in the literature. In this case report, as it was difficult to determine whether phenobarbital or acetylsalicylic acid was responsible for this reaction, subsequent patch tests allowed the identification of the culprit component since it was positive to phenobarbital.

Carbamazepine-induced DRESS and HHV6 primary infection: the importance of skin tests.

SUMMARY: A 34-year-old male with a 20-year history of epilepsy was treated with valproic acid and phenobarbital. As he had frequent convulsive fits, carbamazepine (CBZ) was added. Thirty-four days later, the patient developed hyperthermia, (39.5 degrees C), cervical lymphadenopathy and generalized cutaneous exfoliated maculae and papulae. Biochemical investigation was characterized by a white cell count of 16.1 x 103/microl (17% eosinophils) and increased levels of aspartate aminotransferase and alanine aminotransferase (50 and 116 IU/L, respectively). HHV6 serological tests performed on day 21, detected anti HHV6 IgM, suggesting a HHV6 primary infection. Hence, CBZ was discontinued. One month later, the skin eruption, fever, lymph node swelling, liver dysfunction, and eosinophilia were progressively relieved. Six weeks after complete recovery, prick and patch skin tests were performed. They were strongly positive at 48-h reading. This report suggests the usefulness of skin tests in diagnosing CBZ-induced-DRESS, as well as s possible association between DRESS and HHV6 primary infection.

Acenocoumarol and vasculitis: a case report.

A 62-year-old woman was referred to the dermatology department for a history of fever, asthenia and cutaneous rash, which appeared after a 3-day course of digitalin and acenocoumarol for atrial fibrillation. The physical examination revealed multiple round confluent purpuric lesions over her entire legs with no blistering. Laboratory exams were all negative. Biopsy of the involved skin was compatible with leucocytoclastic vasculitis. The acenocoumarol treatment was withheld and the skin lesions resolved spontaneously over the next 10 days. The cause of this purpura was seemingly acenocoumarol because of the close temporal relationship between exposure to the drug and the onset of the symptoms, and the spontaneous resolution of the lesions after acenocoumarol was discontinued. This observation illustrates a rare association between vasculitis and acenocoumarol. Clinicians should be aware of this potential adverse effect and recommend interrupting the drug intake when temporal relation is evocative.