Background: It has remained unclear whether genetic background of patients with atopic eczema (AE) alone is identical to that of patients with both AE and atopic respiratory disease.
Objective: We aimed to assess whether there is a genetic difference between these two groups of AE patients.
Method: We determined the genotype with regard to an allelic polymorphism in the gene for mast cell chymase (MCC; a serine protease secreted from mast cells) in 169 AE patients.
Results: MCC genotype was significantly associated with pure AE patients who did not have a predisposition to atopic respiratory disease and whose serum IgE concentration was < 500 IU/mL. The distribution of MCC genotypes also differed significantly between the latter patients and those AE patients with bronchial asthma and a serum IgE concentration of > 2000 IU/mL.
Conclusion: These results suggest that pure AE is associated with genetic variants of MCC, and that the genetic basis of pure AE differs from that of AE associated with atopic asthma.