Photodistributed chickenpox in a 3-year-old boy

A case of photodistributed chickenpox in a 3-year-old boy is presented. Ultraviolet (UV) rays are known to exacerbate cutaneous herpes infection, but photodistributed chickenpox is an atypical presentation. In photodistributed disease, skin lesions are slightly larger than in typical chickenpox (usually 1-2 mm), the rash is monomorphous and the lesions are in a similar stage of evolution. The pathogenesis remains unclear, although it is proposed that UV rays induce local vasodilatation and increase capillary permeability, particularly during viremia.