photodermatology

Introduction

UV light:
- exposure to UV light is important in generating vitamin D
- excessive UV light will cause sunburn, tanning, increased freckles and moles, photodermatoses, skin ageing and risk of skin cancer
- photodermatoses are abnormal skin responses to exposure to light and/or UV light causing rashes
- UV light is also used as phototherapy for various conditions such as psoriasis
visible light:
- intense blue light can also cause skin redness, increase melasma, contribute to post-inflammatory hyperpigmentation and some photodermatoses, especially in darker skinned individuals¹⁾
infrared light (radiant heat):
- acute intense exposures to infrared light can cause skin burns
- chronic high exposures to infrared light can cause erythema ab igne skin pigmentation

¹⁾