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Sun allergy may appear under the influence of medications. This was the case with this woman. After taking antibiotics and exposure to the sun, she developed hives all over her body. What is the cause of the allergy and what is the treatment? See the photos and read the dermatologist's comment.


  1. Sun allergy after antibiotic - symptoms
  2. Sun allergy after antibiotic (urticaria) - treatment
  3. Drugs that may cause allergy to the sun
  4. Sensitization to the sun - phototoxic or photoallergic reaction

Sun allergy after antibioticsurprised our reader, who decided to write about it to our editorial office to warn others. Extensive, massive urticaria appeared on the woman's body after a few days of antibiotic treatment (first with a broad-spectrum semi-synthetic penicillin, then an antibiotic from the tetracycline group was introduced).

The woman was receiving treatment for a prolonged throat infection. At the same time, she did not protect herself from the sun. She went to work, went shopping, and walked in the park. It was enough for a photoallergic reaction to occur, i.e. drug allergy to the sun (photodermatosis). Itchy and painful hives covered her whole body.

These photos were taken on day 1.

Sun allergy after antibiotic - symptoms

Here is a fragment of an e-mail from our reader:

“I was woken up by itchy skin. The sheets felt irritating to my body. When I picked up the covers, I saw hives on my legs, abdomen, forearms. Red lumps covered almost the entire body, all the way to the chin line. It stabbed as if every touch was like sticking needles. Especially on the legs. I couldn't wear long pants. The rash was itchy on the back and stomach. It was a day off from work, I reported to the HED. The doctor suggested it was the result of sunbathing while taking antibiotics, but I wasn't lounging on the beach at all! Yes, I wore shorts and T-shirts. You can't do otherwise when it's hot outside. "

Sun allergy after antibiotic (urticaria) - treatment

An antibiotic sun allergy is a reaction that you can read about in the package insert. Such a warning is in the description of one of the antibiotics thatwas accepted by a woman:

"During the treatment period, exposure to sunlight or UV radiation (eg in a solarium) should be avoided, due to the risk of skin photosensitivity reactions."

The second drug, among the common side effects, had a rash and itching.

Fortunately, the hives from the sun and antibiotics became less and less troublesome with each passing day, mainly due to the medications that are given to treat urticaria.

Here is another fragment of the e-mail: “For the next week I used the prescribed ointment and an antihistamine. The hives became paler and less itchy. The longest, more than 2 weeks, she stayed on her feet. "

These photos were taken on the 3rd day.

According to an expertBartosz Pawlikowski, specialist in dermatology, Pawlikowski Clinic in Łódź

In the case of very severe changes covering a large area of ​​the skin, you should immediately report to the nearest doctor or hospital. A dynamically developing allergic reaction may result in systemic changes: fever, dyspnoea, fainting. Often, such an intense reaction can be life-threatening, and the skin changes may subside, however, leaving behind permanent discoloration.

People who take photosensitizing drugs should stay in the shade or indoors at all times. If this is not possible, use sunscreen, but also wear light clothing that protects against UV rays penetration into the skin.

Drugs that may cause allergy to the sun

Experts divide photodermatitis into idiopathic, where the culprit is the sun itself. But there are also those for which an accomplice is needed, e.g. a photosensitizing substance from outside (it can be an ingredient of a medicine).

Drug-induced photosensitivity reaction occurs when a drug combines with UV radiation, causing a phototoxic or photoallergic reaction. These factors are called photosensitizers, and they can be topical agents or medications that are taken by mouth.

Here is a list of the most common photosensitisers.

  • Antibiotics: tetracyclines, fluoroquinolones, sulfonamides
  • Non-steroidal anti-inflammatory drugs (NSAIDs): ibuprofen, naproxen, ketoprofen
  • Diuretics: furosemide, hydrochlorothiazide
  • Retinoids: isotretinoin, acitretin
  • Drugs used in psychiatry: phenothiazines, thioxanthene
  • Drugs and sun can cause allergies and burns
  • Photosensitizing herbs - which herbs sensitize to the sun? [LIST]

Allergic tosun - phototoxic or photoallergic reaction

Clinical features of drug-induced photosensitivity vary depending on the photosensitive agent used and the type of skin reaction evoked. The reaction may be phototoxic and / or photoallergic.

Phototoxic reactions result from direct tissue damage caused by light activation of the photosensitiser, while photoallergic reactions are a cellular immune response.

Phototoxic reactions:

  • A skin reaction occurs from several minutes to several hours after exposure to the agent and light
  • Appears as an overreaction to sunburn (redness and swelling)
  • Bubbles and blisters may occur in severe reactions
  • The skin lesion may or may not be itchy
  • Reaction limited to sun-exposed skin
  • Separation of the distal nail plate from the nail bed may occur with many oral photosensitizing drugs and may be the only symptom of phototoxicity

Photoallergic reactions:

  • Itchy rash occurs 24-72 hours after exposure to the agent and light
  • May spread to areas that have not been exposed to the sun
  • No discoloration
About the authorJoanna Karwat A journalist specializing in he alth matters. For over 25 years, she has been following trends in medicine and meets doctors to talk about new treatments. She received two distinctions in the "Medical Journalist of the Year 2022" competition in the press journalism category. He spends every free moment playing volleyball. She won gold in the Beach Volleyball Journalists Championship in 2016.

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