Photodermatology

Photodermatology is a branch of dermatology that focuses on the adverse effects of ultraviolet (UV) radiation from sunlight and artificial sources on the skin. It encompasses a wide range of conditions, from acute reactions like sunburn to chronic changes such as photoaging and skin cancer. Understanding the interaction between light and skin is crucial for diagnosis, treatment, and prevention of these disorders.

Common photodermatological conditions include polymorphic light eruption, a recurring rash that appears after sun exposure, and solar urticaria, a hives-like reaction triggered by UV light. Actinic keratoses, considered pre-malignant lesions, and various forms of skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma, are also strongly linked to cumulative sun damage. Photoaging, characterized by wrinkles, sunspots, and loss of skin elasticity, is another significant concern.

Diagnosis often involves a thorough medical history, physical examination of the skin, and sometimes phototesting. Phototesting involves exposing small areas of the skin to controlled doses of UV radiation to identify the specific wavelengths that trigger a reaction and to determine the minimal erythema dose (MED), the lowest dose of UV radiation that causes redness.

Treatment strategies vary depending on the specific condition. Prevention is paramount and includes sun avoidance, wearing protective clothing, and regular use of broad-spectrum sunscreen. For acute conditions, topical corticosteroids and oral antihistamines may be used. Chronic conditions may require ongoing management, including photodynamic therapy or surgical removal of lesions. Education about sun safety is a cornerstone of photodermatological care.