General Thermography
James Stewart Campbell, M. Nathaniel Mead in Human Medical Thermography, 2023
Sunburn involves a different damage mechanism, quite distinct from thermal burns. Thermal burns are caused by excess infrared (IR) exposure, which can penetrate deeply by conduction. Sunburn is caused by excess ultraviolet (UV) exposure, which does not penetrate the skin deeply or create much heat. UV exposure damages dermal cellular organelles and DNA, causing inflammation. Strong ultraviolet sources other than sunlight can also cause skin damage. Overexposure to a welding arc results in a type of UV burn that appears similar to sunburn, though the distribution over the skin is different. Like welder's burns, overexposure to UV reflecting off snow causes corneal photokeratitis (“snow blindness”) and can damage anatomy not usually affected by sunburn, such as the roof of the mouth or the interior of the nostrils.11
Skin damage from environmental hazards
Ronald Marks, Richard Motley in Common Skin Diseases, 2019
UVB – especially around 290 nm – is mainly responsible for sunburn, suntan and skin cancer, although other wavelengths contribute to the pathogenesis of these conditions. UVB only penetrates as far as the basal layer of the epidermis, but causes the death of scattered keratinocytes (sunburn cells) and damages others, so that they release cytokines and mediators. These produce oedema, vasodilation and a subepidermal inflammatory cell infiltrate. About 2 days after UVR injury, there is an increase in the rate of melanin synthesis. It is probably not possible to stimulate a tan without sustaining UVR-induced epidermal damage. Sunburn is easily recognized by the redness and, when severe, swelling and blistering as well. It is quite sharply restricted to the area of skin exposed. The affected area is very sore and, if blistered and extensive, makes the individual feel unwell and even requires inpatient management as for a thermal burn.
UV Radiation in Melanoma Development and Pathogenesis
Sanjiv S. Agarwala, Vernon K. Sondak in Melanoma, 2008
While there is no standard measure, sun exposure can be generally classified as intermittent or chronic, and the effects may be considered as acute or cumulative. Intermittent sun exposure is that obtained sporadically, usually during recreational activities and particularly by indoor workers who have only weekends or vacations to be outdoors and whose skin has not adapted to the sun. Chronic sun exposure is incurred by consistent sun exposure, usually by outdoor work, but also among those people who are outdoors a great deal. Acute sun exposure is that obtained over a short time period on skin that has not adapted to the sun. Depending on the time of day and the skin type of the individual, acute sun exposure may result in sunburn. Sunburn in epidemiology studies is usually defined as burn with pain and/or blistering for two or more days.
Preparation and optimization of silibinin-loaded chitosan–fucoidan hydrogel: an in vivo evaluation of skin protection against UVB
Published in Pharmaceutical Development and Technology, 2021
Masood Ali Karami, Behzad Sharif Makhmalzadeh, Mahsa Pooranian, Anahita Rezai
Protective effects of different groups on UVB irradiation-induced skin injury, A: Skin thickness; B: Number of sunburn cells per field, C: Histological images. 10 mg/cm2 of all formulations were applied before UVB expose to the skin and the skin thickness and sunburn cells were measured 24 h after the UVB irradiation; ###p ˂ 0.001 when compared with the normal un-irradiated skin (group 1), *p ˂ 005, **p ˂ 001, and ***p ˂ 0001 when compared with the untreated irradiated group (group 2). 1: Normal un-irradiated skin, 2: untreated irradiated skin, 3:irradiated skin treated by blank hydrogel, 4: irradiated skin treated by 100 µM SB aqueous suspension, 5: irradiated skin treated by 100 µM SB hydrogel, 6: irradiated skin treated by 200 µM SB hydrogel, 7: irradiated skin treated by 250 µM SB hydrogel, 8: irradiated skin treated by 350 µM SB hydrogel, 9: irradiated skin treated by 450 µM SB hydrogel, and 10: irradiated skin treated by Trademark sunscreen (positive control).
Redefining electrosensitivity: A new literature-supported model
Published in Electromagnetic Biology and Medicine, 2021
Mary Redmayne, Siobhan Reddel
If the hypo-aware individual’s repair mechanism and immune system cannot keep up in the presence of chronic RFR exposure stress, then the person may accumulate cellular and further damage until eventually a disease becomes apparent, maybe years later (top right side of figure 1). An eventual onset of glioblastoma related to the person’s extent of mobile phone use over the years (Hardell et al. 2011; Levis et al. 2011; Yang et al. 2017) would be an example of this, representing a catastrophic event as discussed in Catastrophe Theory (Davis et al. 2019; Levine 1976). A shorter-term analogy from sunlight exposure is not feeling sunburn, sometimes even if it can be seen, and thus potentially continuing to sunbathe.4Recognising that there can be emotive/esteem advantages to both phone calls and sunbathing that could influence over-ride of feedback.Autoimmune disease and conditions
Skin cancer awareness and sunscreen use among outpatients of a South African hospital: need for vigorous public education
Published in South African Family Practice, 2018
NC Dlova, R Gathers, J Tsoka-Gwegweni, RJ Hift
The benefits of sunscreen are not restricted to cancer prevention. Sunscreen may reduce wrinkling and photo damage, resulting in more even pigmentation. With age, darker skin types are more likely to demonstrate skin mottling and uneven skin pigmentation.18,19 Our results suggest a general lack of understanding of the link between light skin, propensity for sunburn, risk of melanoma and of the role of sun protection in ameliorating this risk. Though most white respondents are appropriately aware that regular use of sunscreen may prevent skin cancer and understand the concept of sun-protection factor, it is concerning that 41% have not understood that sunburn is a form of skin injury, and only 21% expressed an awareness of the need for regular use of sunscreen.