Lamotrigine hypersensitivity

I asked Dr. Eric Macy, expert in drug allergy, to provide his input. His response is as follows:
"Lamotrigine is not associated with IgE-mediated allergy and prick and intradermal skin testing is not useful in evaluating lamotrigine associated immunologically-mediated hypersensitivity.

Lamotrigine is associated with severe T-cell mediated delayed type hypersensitivity and can be fatal.
Patch testing has been used to confirm that lamotrigine was the causative agent.

Most cases of lamotrigine-associated anticonvulsant hypersensitivity syndrome occur in the first 8 to 12 weeks of treatment, with the onset of fever, lymphadenopathy, and cough.

If the index reaction was only a benign rash without systemic symptoms, then rechallenge, if needed, can be attempted.

Close monitoring is essential for the first several months, if rechallenge is attempted.
Check liver function tests and blood counts for eosinophilia.
If any rashes appears, have them biopsied to confirm that it is a drug eruption.

There is no data that I am aware of on T-cell mediated cross reactivity between lamotrigine and carbamazepine, but both can cause these severe delayed onset T-cell mediated hypersensitivity reactions."

I hope you find this information helpful.

Regards,
Daniel Jackson, MD FAAAAI