Medications such as substances that are outside the body may also be a cause of allergy when given to patients sensitive to them. Allergic reactions to medicines are the most common immediate-type, such as hives, asthma, and, very exceptionally, anaphylactic shock with loss of consciousness and respiratory problems. With some medications can also cause more delayed-type allergies, also can be serious.
There are also known photoallergic reactions caused by exposure to sunlight when taking the drug. Normally cause the appearance of red spots on exposed skin (including short-lived). This is the case of some drugs such as antibiotics, diuretics, etc., But also of certain perfumes and medicinal plants.
In this case, the light acts on the drug (or the product of its transformation) by allergic mechanisms. Sun exposure does not cause any demonstrations until it has developed sensitization or allergy. Once introduced this sensitivity, the photoallergic reaction occurs whenever there is sun exposure and are taking certain medications, regardless of dose and duration and intensity of exposure. (more…)