Hydroa vacciniforme. Diagnosis by repetitive ultraviolet-A phototesting

Hydroa vacciniforme

“…In our patient there was a moderate decrease in the minimal erythema dose for UVA, a result which corre sponded to some of the previously reported cases [1,6]. However, we could not induce the formation of typical HV lesions with repeated exposures, as were reported by some authors [5][6][7][8][9], The pathogenesis of HV is still unknown. Some authors suspected a deficit in vitamin B", conse quently altering tryptophan metabolism; however, vitamin B(, substitution did not improve the symptoms [2,10], Treatment is often unsatisfactory, measures occasionally reported to be of some benefit were antimalarials, p-carotenes and eventually phototherapy [1][2][3]11].…”

Hydroa vacciniforme presenting in an adult successfully treated with cyclosporin A

“…Similarly dermal oedema may occasionally result in blister formation in polymorphic light eruption but this is subepidermal, while epidermal necrosis is not a feature. 11 Sub-epidermal blistering can also be seen in PCT, but can usually be distinguished by the relative paucity of inflammatory cells in the dermis and peroxidase acid Schiff-positive material deposited around vessels. Finally, the immunofluorescence findings of HV are usually negative although some studies have shown C3 deposits below the basement membrane zone.…”

A Case of Hydroa Vacciniforme

“…HV is a very rare photodermatosis of unknown etiology that principally starts in childhood 4 . It has several distinctive features, including the (1) uniform development of vesicles and crusts several hours to 1 or 2 days after sun exposure, (2) healing of lesions with varioliform scarring, (3) absence of laboratory abnormalities, including serologic and porphyrin studies, (4) characteristic histopathology with epidermal necrosis and intraepidermal vesiculation, and (5) demonstrable evocation of the typical lesions by exposure to light 5 .…”

“…The differential diagnosis of HV consists of several blistering disorders that are light induced, including EPP, vesicular polymorphous light eruption (PMLE), bullous lupus erythematosus, solar urticaria, hydroa aestivale and porphyria cutanea tarda (PCT) 4,5 . Physicians can distinguish between these different illnesses in most cases by obtaining detailed historical, clinical, histopathologic and laboratory data.…”