What are the links between sun and medication use?
Ask your doctor or pharmacist if you are taking medications if they increase photosensitivity. Some medications (steroids, hormones) in particular cause hyperpigmentation, which is increased by sunlight. A typical example is the contraceptive pill: in combination with sun rays, brown spots appear. The same pigmentation disorders can also occur during pregnancy. Photosensitization refers to the lowering of the skin‘s light stimulus threshold. This can be caused by substances acting on the skin from the outside or from the inside. Among these substances, there are a variety of drugs. One can distinguish photoallergic and phototoxic reactions. Various symptoms may occur as a result of exposure to the substances:
- Increased sunburn
- Erythema (extensive reddening of the skin)
- Change in pigmentation
- Pseudoporphyria – change in the skin with increased vulnerability and blistering.
- Photoonycholysis – detachment of the nail plate.
- Lichenoid reactions – lichen-like skin changes.
- Subcorneal pustule formation – pustule formation occurring under the cornea of the eye.
- Subacute cutaneous lupus erythematosus – systemic autoimmune disease from the group of collagenoses with scattered foci of skin and firm scaling.
- Phototoxic purpura – small capillary bleeding in the skin.
- Photocarcinogenesis – development of malignant cutaneous neoplasms (malignant neoplasms of the skin) such as squamous cell carcinoma.
Almost every second drug prescribed in German-speaking countries can provoke skin reactions due to photosensitivity:
Photosensitizing drugs (drugs that can cause photosensitivity or photosensitivity) include mainly:
| Drug group | Active ingredient | Active ingredient group | Active ingredient |
| Antidepressants | Amitriptyline | Diuretics | Amiloride |
| Clomiramine | Bendroflumethiazide | ||
| Desipramine | Etycrynic acid | ||
| Doxepin | Furosemide | ||
| Imipramine | Hydrochlorothiazide (HCT) | ||
| Nortriptyline | Spironolactone | ||
| Trimipramine | Triamterene | ||
| Antiepileptic drugs | Carbamazepine | Xipamide | |
| Lamotrigine | Hormones | Corticosteroids | |
| Phenobarbital | Estrogens | ||
| Phenytoin | Progesterone | ||
| Topiramate | Spironolactone | ||
| Valproic acid | Cardiovascular active substances | Amiodarone | |
| Antihistamines | Cyproheptadine | Captopril | |
| Diphehydramine | Quinidine | ||
| Loratadine | Disopyramide | ||
| Antimicrobial substances | Ciprofloxacin | Enalapril | |
| Doxycycline | Fosinopril | ||
| Enoxacin | Hydralazine | ||
| Gentamycin | Nifedipine | ||
| Griseofulvin | Ramipril | ||
| Isoniazid | Simvastatin | ||
| Lomefloxacin | Nonsteroidal anti-inflammatory drugs | Diclofenac | |
| Minocycline | Ibuprofen | ||
| Nitrofurantoin | Indometacin | ||
| Norfloxacin | Ketoprofen | ||
| Ofloxacin | Mefenamic acid | ||
| Oxytetracycline | Naproxen | ||
| Sulfamethoxazole/trimethoprim | Phenylbutazone | ||
| Sulfasalazine | Tiaprofenic acid | ||
| Antipsychotics | Chlorpromazine | Substances against malaria | Quinine |
| Chlorprothixene | Chloroquine | ||
| Fluphenazine | Hydroxychloroquine | ||
| Haloperidol | Mefloquine | ||
| Perazine | Pyrimethamine | ||
| Promethazine | Cytotoxic substances | Azathioprine | |
| Promazine | Dacarbazine | ||
| Thioridazine | Fluorouracil | ||
| Systemic dermatics | Isotretinoin | Methotrexate (MTX) | |
| Methoxsalen | Procarbazine | ||
| Other | Gold salts | Vinblastine | |
| Hematoporphyrin |
Diagnostic procedure for suspected phototoxic/photoallergic reaction:
- Light staircase examination with determination of minimal erythema doses – Cave: do not discontinue medication beforehand.
Prophylactic measures
- Take medications with a short half-life in the evening
- Avoid solariums
- Avoid sunlight between 11 am and 3 pm
- Apply sunscreen with high UV-A protection
- Wear textiles with light protection
- For long-term use: attach UV-impermeable films to windows
Therapeutic measures
- Topical glucocorticoids, if necessary in combination with antiseptics.
- Burn therapy for extensive blistering reactions.
- Hydroquinone (5%), hydrocortisone (1%) and tretinoin (0.1%) should be used for hyperpigmentation
- In exceptional cases, laser treatment is indicated (for amiodarone or minocycline pigmentation).
Further notes
- In addition to drugs, there are other substances that increase photosensitivity. Such substances are saccharin, lemon or lime oil, and certain dyes and fragrances.
- Avoid fragrances that contain bergamot or lemon oil, as they can cause brown spots on the skin when exposed to UV light.
What can you do about unwanted pigmentation?
Ask your attending physician about this. In general, apply sunscreen with a high sun protection factor! Exfoliation or peeling will make the skin tone more even, because excess skin flakes are removed from the surface. Use an opaque makeup that serves as a mechanical sunblock and conceals skin tone irregularities.