Background: Summer and spring eruptions on the elbows are a variant
of polymorphous light eruption described on clinical and histopathological
grounds; however, to our knowledge, they have not been confirmed by
photobiological studies.
Objective: Based on photobiological studies, this study aimed to demonstrate the
involvement of ultraviolet-A (UVA) radiation in this variant of polymorphous light
eruption occurring exclusively on the elbows.
Methods: A series of five patients with polymorphous light eruption lesions
on the elbows were included in our study. All patients underwent phototesting
and photoprovocation of the skin lesions after exposure to a UVA light source
[Philips UVA HPA lamp (400 W)]. All patients underwent punch biopsy and
histopathological and immunohistochemical studies with anti-CD123.
Results: In all the cases, UVA irradiation caused the appearance of skin lesions
on the elbows with characteristic polymorphous light eruption. Histological data
showed edema in the superficial dermis and a perivascular lymphocytic infiltrate
compatible with polymorphous light eruption. Immunohistochemical staining for
CD1-23 showed negative results.
Conclusions: For the first time, photobiological photoprovocation studies
demonstrated that repeated exposure to UVA radiation leads to the generation
of skin lesions on the elbows, which are clinically and histologically consistent
with summer and spring eruptions, confirming that elbow rash is a variant of
polymorphous light eruption
