True photoallergy to sunscreens is rare despite popular belief.
BACKGROUND
Rising use of sunscreen products has led to increased reporting of adverse reactions to sunscreens.


OBJECTIVE
To investigate possible photoallergic reactions in patients who identified themselves as "being allergic" to sunscreens.


METHODS
Patients filled out questionnaires about types of sunscreens they used and timing of their "allergic" reactions. Next, they consented to be photopatch-tested with active sunscreen ingredients, including the new sunscreen Anthelios SX (containing Mexoryl SX) and the new ultraviolet filters Tinosorb M and Tinosorb S. Standard allergen patch testing was also done.


RESULTS
Twenty-seven patients self-reported "sunscreen allergy." Photopatch testing is difficult for patients; hence, only 11 agreed to proceed with the testing. Eight patients had negative patch testing results. One patient reacted to benzophenone-2. Another had a prior reaction to titanium dioxide and titanium oxalate but did not react to the silicone-coated titanium in our study. Yet another patient had relevant photopatch reactions to benzophenone-3 and ethylhexyl dimethyl para-aminobenzoic acid (PABA). None reacted to the Tinosorbs or Anthelios SX. Few positive reactions to the standard allergens were not relevant.


CONCLUSIONS
Although small, this study parallels prior studies in concluding that true delayed type IV hypersensitivity (allergic contact dermatitis and photoallergy) to sunscreens is more infrequent than patients tend to believe.
Shaw
Tatyana
T
Dermatology Department, Oregon Health & Science University, Portland, OR, USA.
Simpson
Brenda
B
Wilson
Brittney
B
Oostman
Holly
H
Rainey
David
D
Storrs
Frances
F
D010129:4-Aminobenzoic Acid / Q000009:adverse effects; D001577:Benzophenones / Q000009:adverse effects; D001892:Camphanes / Q000009:adverse effects; D047188:Chalcones / Q000009:adverse effects; D003487:Cyanoacrylates / Q000009:adverse effects; D017454:Dermatitis, Photoallergic / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010070:Oxalates / Q000009:adverse effects; D010328:Patch Tests; D010636:Phenols / Q000009:adverse effects; D013451:Sulfonic Acids / Q000009:adverse effects; D013473:Sunscreening Agents / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014025:Titanium / Q000009:adverse effects; D014227:Triazines / Q000009:adverse effects
D001577:Benzophenones; D001892:Camphanes; D047188:Chalcones; D003487:Cyanoacrylates; D004338:Drug Combinations; D010070:Oxalates; D010636:Phenols; D013451:Sulfonic Acids; D013473:Sunscreening Agents; D014227:Triazines; C518067:avobenzone, ecamsule, octocrilene drug combination; C500403:methylene bis-benzotriazolyl tetramethylphenol; C075352:terephthalylidene dicamphor sulfonic acid; C009495:titanium dioxide; D014025:Titanium; C035476:2,2',4,4'-tetrahydroxybenzophenone; C439083:bis-ethylhexyloxyphenol methoxyphenyl triazine; D010129:4-Aminobenzoic Acid