Individuals exhibiting conspicuous nevi (lentigo simplex) are resistant to allergic rhinitis/conjunctivitis (pollinosis), but those who do not show increased susceptibility to pollinosis.

We investigated 115 individuals in Tokyo from two groups of persons with conspicuous nevi on the head, neck, and arms, etc. (nevus-positive group) and persons who do not exhibit such nevi (nevi-negative group) interviewing them to determine whether they suffered from allergic rhinitis/conjunctivitis (pollinosis) and examining them for the presence and extent of nevi. There was a distinct correlation: only 5 persons among 85 individuals of the nevus-positive group suffered from pollinosis, and all 30 people in the nevus-negative group had pollinosis. Thus, individuals exhibiting conspicuous nevi are resistant to pollinosis, but those who do not show increased susceptibility to pollinosis.