Doxycycline is a commonly prescribed antibiotic belonging to the tetracycline class, used to treat various bacterial infections like pneumonia, acne, and Lyme disease, and also to prevent malaria. While effective, this medication is known to increase the skin’s sensitivity to sunlight, a side effect called photosensitivity. This interaction means that exposure to the sun while taking doxycycline can lead to potentially severe skin reactions.
The Sun’s Effect on Your Skin
When taking doxycycline, even brief sun exposure can trigger a phototoxic reaction, which resembles a severe sunburn. This reaction often manifests as intense redness, pain, and itching. Blistering, peeling, or widespread rash can also occur, appearing within minutes to hours of exposure. The skin can weep, and a burning sensation may occur. Unlike an allergic reaction, this is a direct chemical interaction between the drug and ultraviolet (UV) light.
How Doxycycline Causes Sun Sensitivity
The photosensitivity caused by doxycycline occurs because the drug molecules absorb UV light, particularly UVA radiation, when they accumulate in the skin. This absorption of light energy triggers a chemical reaction within the skin cells. This process leads to the generation of reactive oxygen species, which are unstable molecules that can damage skin cells and cause an inflammatory response. The risk of this reaction is influenced by factors such as the dose of doxycycline, the intensity of UV exposure, and individual susceptibility.
Protecting Yourself and Responding to Reactions
Protecting Yourself
Protecting your skin from the sun is important while taking doxycycline, and for up to two weeks after stopping the medication, as the drug can remain in your system. Seek shade, especially during peak sun hours between 10:00 a.m. and 4:00 p.m., when UV radiation is strongest. Wearing protective clothing, such as long-sleeved shirts, pants, wide-brimmed hats, and sunglasses, creates a physical barrier. Apply a broad-spectrum sunscreen with an SPF of 30 or higher to all exposed skin, reapplying every two hours, or more often if swimming or sweating. Avoid tanning beds and sun lamps.
Responding to Reactions
If a sun reaction occurs despite precautions, immediately move out of the sun and into a shaded area. Cooling the affected skin with cool compresses or a cool bath can alleviate discomfort. Over-the-counter topical treatments like aloe vera gel or hydrocortisone cream may soothe the skin and reduce inflammation. If the reaction is severe, involving extensive blistering, a widespread rash, or signs of infection, seek medical attention promptly. Your doctor can provide further guidance and may recommend adjusting your medication or prescribing stronger treatments.