Familial erythromelanosis follicularis and chromosomal instability.
We report a 17-year-old male patient with erythromelanosis follicularis faciei et colli (EFFC), oral leucokeratosis and diabetes mellitus without islet cell antibody. His sister also had minimal findings of EFFC and minimal follicular papules on her shoulders and extensor surfaces of the arms. The father had only fine follicular papules, but no erythromelanosis. Skin and mucous membrane lesions of the proband were investigated histopathologically. Interestingly, in peripheral lymphocyte cultures of the family members, chromosomal breakage was not observed spontaneously, but it was seen with nitrogen mustard, although this disease may be of autosomal recessive inheritance. Thus, we suggest that EFFC may be a polyaetiological disorder (i.e. familial and environmental) and might be considered one of the chromosomal instability syndromes.