Some treatments make the skin more sensitive to the effects of the sun. Here are which ones.
- In case of phototoxicity, a painful “sunburn” type skin reaction is triggered by the photosensitizing drug under the activation of the sun’s rays.
- In predisposed and pre-sensitized adults, any re-exposure to the sun, even with minimal doses of UV, leads to a photoallergic reaction.
- To know if a drug has a photosensitizing effect, it is advisable to check the presence of a pictogram representing a sun behind a cloud on its box.
Do you have to take medication during the summer period? Be careful, some can be photosensitizing. Clearly, they act as a chromophore, namely a molecule that can change color in response to light excitation, according to the French Network of Regional Pharmacovigilance Centers (RFCRP). We speak of drug photosensitization when an abnormal and disproportionate reaction of the skin is observed after an interaction between sun exposure and a “photosensitizing” drug.
Photosensitization: a photochemical reaction or drug allergy
There are two types of photosensitization reactions. The first is phototoxicity. “The drug triggers in a few hours, under the activation of the sun’s rays, a painful skin reaction of the ‘sunburn’ type, sometimes with bubbles, exaggerated compared to sun exposure. The location always corresponds to the exposed area (…) The intensity of the reaction presented depends on the intensity of sun exposure, the drug, the dose administered, as well as the phototype of the individual.A person with a clear phototype will be more sensitive than a person with a dark phototype, but a phototoxic reaction remains possible with darker skin”, explains the RFCRP on its website.
Although the cases are more rare, it can also be a photoallergy. This allergic drug reaction occurs in predisposed and pre-sensitized people 5 to 21 days after taking or applying the drug. In this case, any solar re-exposure to this drug, even with minimal doses of UV, causes a photoallergic reaction. The lesions, which look like eczema or hives, can reach the covered areas. The reaction disappears after stopping treatment.
What medications should be avoided when exposed to the sun?
Among the drug families containing photosensitizing specialties, we find:
- Antibiotics
- birth control pills
- Anti-acne ointments
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Antidepressants
- Diuretics
- Anti-cancer drugs
- Oral antidiabetic treatments
“Photosensitizing drugs have a distinctive symbol (pictogram) on their box in order to easily identify them and thus take the appropriate preventive measures”, indicates the French Network of Regional Pharmacovigilance Centers.