OBJECTIVETo investigate the susceptibility of trichloroethylene-induced medicamentosa like dermatitis by comparing the frequency of HLA-DMA and HLA-DMB in patients with trichloroethylene-induced medicamentosa like dermatitis and in normal controls.

METHODSThe DNA of lymphocytes in 61 patients with trichloroethylene-induced medicamentosa like dermatitis and in 60 people as the normal control were abstracted by using touchdown PCR amplification of HLA-DMA and HLA-DMB. Then through restriction fragment length polymorphism (RFLP) and sequence base typing, the alleles and genotypes were confirmed. The frequency of HLA-DMA and HLA-DMB in the two groups was compared.

RESULTSThe HLA-DMA*0101 allele frequency in patients with trichloroethylene-induced medicamentosa like dermatitis was significantly higher than in the control group (71.3% vs 55.0%, P < 0.05). The allele frequency of HLA-DMA*0103 was significantly higher in the patient group than in the control group (11.5% vs 3.3%, P < 0.05). The ratio of *0102 homozygotes of HLA-DMA*0102 in the patient group was significantly higher than in the control group (25.0% vs 8.2%, P < 0.05). The ratio of *0102 heterozygotes of HLA-DMB*0101 in the patient group was lower than in the control group (P < 0.05).

CONCLUSIONThe polymorphisms of DMA may be related to the susceptibility of the patients with trichloroethylene-induced medicamentosa like dermatitis.