Light sensitivity or photosensitivity means sensitivity of the skin to light rays, most commonly to Ultraviolet radiations (less commonly visible light) coming from the sun or from any other light source. It results from the abnormal reaction of the skin to the light energy.
Symptoms of Light Sensitivity are seen in many disorders and these disorders can be classified into three broad groups-
1. Phototoxic skin reactions – they occur immediately following light exposure (acute onset) and no prior sensitization is required. Severity of the reaction is related to the amount of light exposure. And symptoms improve quickly when there is no further sun exposure. (Sun Burn, Drug induced, Genodermatoses)
2. Photo allergic skin diseases- skin eruption appears gradually following sun exposure and takes variable period of time to subside. Prior sensitization is required. (PMLE, Drug induced, Photo contact Dermatitis, Solar Urticaria, Actinic Prurigo, Connective Tissue diseases like SLE & Dermatomyositis)
3. Photo aggravated skin diseases- light rays are not the primary culprit but the disease worsens on light exposure. (Atopic dermatitis, Pellagra)
Phototesting and photo patch testing are the specific tests for disorders of light sensitivity. Other investigations like skin biopsy, blood tests are decided based on the associated disease suspected. Treatment
All the diseases of light sensitivity improve with sun protective measures. Other than that treatment is different for different light sensitivity disorders. Sun protective Measures are all the measures that you can take to prevent your skin from light damage. This includes-
Does artificial light sources at home and offices and light form mobile and laptop screen harm the skin of light sensitive person?
Lots of research has been done on the effect of UV rays on skin but during last decade researchers have also got interested in the effect of visible light on skin. Current understanding is –