[Erythema gyratum repens: drug reaction following azathioprine administration in a patient with type I autoimmune hepatitis].

BACKGROUND: Erythema gyratum repens is a rare, clinically specific, and distinctive paraneoplastic syndrome.

CASE REPORT: A case of erythema gyratum repens in a 76-year-old woman with autoimmune hepatitis type I treated with glucocorticoids is reported. Within 3 weeks of supplementary azathioprine treatment, the patient reported gastrointestinal discomfort and developed an erythema gyratum repens confined to the abdomen, thighs and knees. Azathioprine medication was stopped and the dermatologic features resolved completely after a period of 1 week. Absence of any demonstrable underlying malignancy was confirmed by different tests. Molecular diagnosis detected heterozygous G460A and A719G transitions in the thiopurine methyltransferase (TPMT) gene. 18 month later, complete remission on maintenance therapy (prednisone 7.5 mg) was observed with further absence of malignancy.

CONCLUSION: This is the first report of an erythema gyratum repens in association with azathioprine treatment in an autoimmune hepatitis type I patient with proven common polymorphism in the TPMT gene.