Carbamazepine is a drug widely used in the treatment of epilepsy, trigeminal neuralgia and affective disorders.
Cutaneous reactions: 3 to 16%.
Stevens-Johnson’s syndrome: 1/5000 to 1/10000.
(occurring one week to 3 months (average 4 weeks) after starting therapy)
Carbamazepine hypersensitivity syndrome: fever + lympha-denopathy (pseudolymphoma syndrome) + generalized rash.
Other: serum sickness, glandular fever-like syndrome, Kawasaki-like syndrome, systemic lupus erythematosus-like syndrome, hypersensitivity vasculitis, necrotizing granulomatous vasculitis.
Cutaneous: macular or maculopapular rash, eczematoid dermatitis, edema of the face, hands and feet, purpura, erythroderma, urticaria, exfoliative dermatitis, erythema multiforme, toxic epidermal necrolysis.
Respiratory: cough, dyspnea, pneumonitis.
Digestive: hepatosplenomegaly, hepatitis
Renal: acute tubulointerstitial nephritis, hypersensitivity vasculitis.
Hematological: leukocytosis, eosinophilia, leukopenia, lymphopenia, agranulocytosis, aplastic anemia, thrombocytopenia.
Haye’s patch-tests chambers: carbamazepine 100%, 10%, 1% and 0.1% in pet. jelly and in acetone: positive in patients with carbamazepine hypersensitivity syndrome.
Lymphocyte transformation test: positive in patient with carbamazepine hypersensitivity syndrome.
Highly reactive arene oxide or epoxide metabolites formed by cytochrome P 450, or other metabolites formed by myeloperoxidase bind to tissue macromolecules causing cell damage or act as haptens and elicit an immune response.
The results of the patch-tests and lymphocyte transformation tests indicate the presence of a specific T-cell reactivity.
Anticarbamazepine antibodies have been detected.
Presence of immunosuppressive cytokines, production of numerous auto-antibodies, deposits of immune complexes in the skin.
Systemic corticosteroids are recommended in the management of carbamazepine hypersensitivity syndrome.
Desensitization is possible (isolated skin rash).
Cross-reactivity between carbamazepine, phenytoin, and phenobarbital is common.