Halo eczema surrounding seborrhoeic keratoses: an example of perilesional nummular dermatitis.

Two patients developed halo eczema around isolated seborrhoeic keratoses and in one individual similar halo eczema developed around the nipples. This phenomenon which was previously described with melanocytic naevi has been associated with a number of different central lesions and can be readily recognised. Both the clinical pattern and histopathology suggest that this phenomenon may represent a localised form of nummular dermatitis with a predilection for elevated lesions.