Atopic dermatitis and melanocytic naevi.

A study was performed to test the clinical impression that adults with severe atopic dermatitis (AD) have a low number of common naevi (CN). The number of CN > or = 2 mm was investigated in 51 Caucasian patients aged 20-63 years with severe AD since early childhood. The control group consisted of 379 randomly selected subjects, aged 30-50 years, investigated in an earlier study. Patients with AD had a significantly (P < 0.0001) lower total body count of CN (mean 9, median 5) compared with the control group (mean 67, median 53). It was also found that in the AD group there was a significant (P < 0.001) negative correlation between serum IgE and number of CN [r(s) = -0.50, 95% CI (-0.69; -0.24)]. The explanation for the low number of naevi that we have found in this highly selected subgroup of AD patients is not known. The atopic inflammation in the skin, genetics and treatment used for eczema are possible factors that may influence the formation of melanocytic naevi.