Photosensitivity, classified as either phototoxic or photoallergic skin reactions, refers to symptoms or conditions caused or exacerbated by an abnormal or intensified response to sunlight exposure. Certain, commonly used, medications may induce photosensitivity, leading to skin reactions ranging in severity. Common photosensitizing medications include hydrochlorothiazide, tetracyclines (such as doxycycline), fluoroquinolones (such as ciprofloxacin), amiodarone, phenothiazines, tricyclic antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs, such as ketoprofen and piroxicam), and several others.
Phototoxic reactions are the most common type of photosensitivity and occur when a medication (or its metabolites) absorb ultraviolet (UV) or visible light and directly damage skin cells via formation of reactive oxygen species. Phototoxic skin reactions manifest as exaggerated sunburn-like reactions with redness, itching, and/or burning, within hours of exposure to the medication and sunlight. Photoallergic reactions are less common, immune-mediated responses triggered by the interaction of a medication (or its metabolites) with sun-exposed skin. The body produces antibodies following this interaction, potentially affecting areas of skin that were not directly exposed to UV light. Photoallergic reactions result in an eczematous eruption that can lead to blister/lesion formation, approximately 24 to 72 hours after exposure.
Photosensitivity reactions are a cause of significant morbidity in affected individuals and, in some cases, may pose a risk for malignancy. Photosensitizing medications enhance the skin’s susceptibility to UV damage by amplifying the harmful effects of UV radiation. Prolonged and excessive exposure to UV radiation from both natural and artificial sources can contribute to an increased risk of skin cancers such as basal cell carcinoma, squamous cell carcinoma and melanoma. Basal cell carcinoma is the most common type of photosensitivity-associated cancer, often occurring in sun-exposed areas such as the face and neck. Squamous cell carcinoma can arise from actinic keratosis, a common skin lesion resulting from sun damage, which may be exacerbated by photosensitizing medications. Photosensitivity-induced inflammation may contribute to the progression of these precancerous lesions and the promotion of an environment conducive to cancer development. Some photosensitizing medications may even cause immunosuppression, further compromising the body’s ability to eliminate damaged cells and prevent the development of cancer. While less directly linked to photosensitivity, the role of UV exposure and certain photosensitizing medications in the development of melanoma is noteworthy.
The link between photosensitivity and cancer underscores the importance of vigilance and regular monitoring, especially in patients on long-term photosensitizing medications. Healthcare providers should educate patients about the potential risks and preventive measures associated with photosensitivity, fostering proactive management, and minimizing the long-term consequences of the condition. Broad spectrum sunscreens with high SPF should be applied before sun exposure and reapplied, as needed. Sunscreen is a crucial component in preventing skin cancer in photosensitive individuals, acting as a barrier to reduce UV penetration, and limiting the formation of reactive oxygen species. Protective clothing such as long-sleeved shirts, pants, and wide-brimmed hats provide physical protection against sunlight. Limiting outdoor activities during peak sunlight hours (10 am to 4 pm) can also reduce the risk of photosensitivity reactions. Finally, encouraging regular skin self-examinations and periodic dermatological assessments can aid in the early detection of suspicious lesions.
Photosensitivity, classified as either phototoxic or photoallergic skin reactions, refers to symptoms or conditions caused or exacerbated by an abnormal or intensified response to sunlight exposure. Certain, commonly used, medications may induce photosensitivity, leading to skin reactions ranging in severity. Common photosensitizing medications include hydrochlorothiazide, tetracyclines (such as doxycycline), fluoroquinolones (such as ciprofloxacin), amiodarone, phenothiazines, tricyclic antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs, such as ketoprofen and piroxicam), and several others.
Phototoxic reactions are the most common type of photosensitivity and occur when a medication (or its metabolites) absorb ultraviolet (UV) or visible light and directly damage skin cells via formation of reactive oxygen species. Phototoxic skin reactions manifest as exaggerated sunburn-like reactions with redness, itching, and/or burning, within hours of exposure to the medication and sunlight. Photoallergic reactions are less common, immune-mediated responses triggered by the interaction of a medication (or its metabolites) with sun-exposed skin. The body produces antibodies following this interaction, potentially affecting areas of skin that were not directly exposed to UV light. Photoallergic reactions result in an eczematous eruption that can lead to blister/lesion formation, approximately 24 to 72 hours after exposure.
Photosensitivity reactions are a cause of significant morbidity in affected individuals and, in some cases, may pose a risk for malignancy. Photosensitizing medications enhance the skin’s susceptibility to UV damage by amplifying the harmful effects of UV radiation. Prolonged and excessive exposure to UV radiation from both natural and artificial sources can contribute to an increased risk of skin cancers such as basal cell carcinoma, squamous cell carcinoma and melanoma. Basal cell carcinoma is the most common type of photosensitivity-associated cancer, often occurring in sun-exposed areas such as the face and neck. Squamous cell carcinoma can arise from actinic keratosis, a common skin lesion resulting from sun damage, which may be exacerbated by photosensitizing medications. Photosensitivity-induced inflammation may contribute to the progression of these precancerous lesions and the promotion of an environment conducive to cancer development. Some photosensitizing medications may even cause immunosuppression, further compromising the body’s ability to eliminate damaged cells and prevent the development of cancer. While less directly linked to photosensitivity, the role of UV exposure and certain photosensitizing medications in the development of melanoma is noteworthy.
The link between photosensitivity and cancer underscores the importance of vigilance and regular monitoring, especially in patients on long-term photosensitizing medications. Healthcare providers should educate patients about the potential risks and preventive measures associated with photosensitivity, fostering proactive management, and minimizing the long-term consequences of the condition. Broad spectrum sunscreens with high SPF should be applied before sun exposure and reapplied, as needed. Sunscreen is a crucial component in preventing skin cancer in photosensitive individuals, acting as a barrier to reduce UV penetration, and limiting the formation of reactive oxygen species. Protective clothing such as long-sleeved shirts, pants, and wide-brimmed hats provide physical protection against sunlight. Limiting outdoor activities during peak sunlight hours (10 am to 4 pm) can also reduce the risk of photosensitivity reactions. Finally, encouraging regular skin self-examinations and periodic dermatological assessments can aid in the early detection of suspicious lesions.
References
Blakely KM, Drucker AM, Rosen CF. Drug-induced photosensitivity – an update: culprit drugs, prevention and management. Drug Saf. 2019 Jul;42(7):827-47. https://link-springer-com.jerome.stjohns.edu/article/10.1007/s40264-019-00806-5
George EA, Baranwal N, Kang JH, et al. Photosensitizing medications and skin cancer: a comprehensive review. Cancers (Basel). 2021 May;13(10):2344. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152064/
Gruber P, Zito PM. Skin Cancer. [updated 2023 May 14]. In: StatPearls [internet]. Treasure Island (FL): StatPearls Publishing. 2023 Jan. https://www.ncbi.nlm.nih.gov/books/NBK441949/
Oakley AM, Badri T, Harris BW. Photosensitivity [updated 2023 Aug 8]. In: StatPearls [internet]. Treasure Island (FL): StatPearls Publishing. 2023 Jan. https://www.ncbi.nlm.nih.gov/books/NBK431072/