The microscopic examination revealed spongiosis and intraepidermal vesiculation with epidermal necrosis and/or dyskeratosis. In the dermis, there was a superficial and deep perivascular lymphocytic and a slight eosinophilic infiltrate (Figure 2 and Figure 3). There was no evidence of vasculitis.
Our patient's previous treatments have included topical steroids, β-carotene, and photoprotection in the form of sun avoidance and sunscreens. They were all minimally effective. Therapy with psoralen–UV-A was considered for desensitization, but given the patient's young age, broad-band UV-B therapy was used during the spring. He developed a slight tan and experienced an extraordinary decrease in his sun sensitivity with increased ability to stay outdoors without provocation of his rash. He also started a summer job, with increased time spent outside daily, thus presumably maintaining his tolerance. Fortunately, with the advent of his teenage years, his problem of UV-induced blistering has greatly diminished. He now manages quite well with 18 annual springtime broad-band UV-B treatments, as long as he is reasonably prudent about sun-protection measures. Titanium dioxide products have not been well tolerated cosmetically.
Blistering, Scarring, and Photosensitivity in a Male Teenager—Diagnosis. Arch Dermatol. 1999;135(10):1267-1272. doi:10.1001/jamadermatol.58601