[Photodistribution of varicella in an adult]

Exacerbation of viral exanthema has been described after different types of aggression such as sun exposure. Photoaggravation of varicella is unusual.

We report the case of a 25 year-old woman who presented with varicella mainly distributed on the neckline and the top of the back. During the viral incubation she had been sunburnt in these areas.

The clinical lesions and the evolution of a photoaggravated varicella differs from those of classical varicella. The vesicles are selectively distributed on areas previously sunburned or suntanned. The more tanned or more erythematous the area is, the greater the number of lesions. They are often at the same stage of development and the course can be shortened with only one or two progressive phases. Inflammatory modifications secondary to ultraviolet exposure induces in photoexposed areas an increase in vascular flow and also an increase in capillary permeability, which can promote diapedesis of the lymphocytes or the transit of viral particles. Therefore, sun exposure during the incubation of the virus can enhance the deposit of viral pArticles in the cutaneous areas submitted actinic stress. The amount of virus in sun exposed areas is greater than in the non-exposed ones.