Summary:
The epidemiology of contact photoallergy in our population is not well known at present.
Therefore the basic aim of our project was to establish the scale of diagnostic methods in the
assessment of skin photosensitivity state by use of photo-patch tests. We tested some substances
(TROLAB® set provided by Hermal comp.). These substances could cause photoallergy, phototoxicity,
and/or contact sensitivity. In the beginning of the studywe have assessed the minimal erythema dose
and its individual seasonal variations to determine the time required for photo-patch testing. The
mean suberythematous UV-A dose of 5 J/cm2 was used.
The group of 27 patients was studied: 17 patients with known photosensitivity in personal history
and 10 persons without photosensitivity as controls. Although in 5 controls (50 %) contact hypersensitivity
was detected, contact allergy was found out also in 8 cases (47 %) of photosensitive group.
Photoallergic reaction appeared on the skin of 2 healthy controls. The incidence of positive photoallergic
responders within the photosensitive group was 5 persons (29.4 %). The results of study
conducted with sunscreens showed that propandione, cinnamates and oxybenzone were the most
frequent photoallergenic substances. These data suggest that some photosensitive troubles could be
caused by a skin response against photoactivated sunscreen components. Thus the physical (nonphotoallergenic)
forms of sunscreens are recommended in essentially sensitive people, especially
when used from childhood.
Key words:
photo-patch test - contact photoallergy - sunscreens
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