Complex pathological reaction: photodermatoses and photodermatitis
Diagnosis and clinical manifestations
Photodermatitis or photodermatosis is a group of diseases induced by solar radiation, in the presence of increased sensitivity to it. Let's figure out what physiological processes in the skin help protect it from the negative effects of ultraviolet light.
The influence of UV rays
About 70% of the spectrum of UVB rays is absorbed by the stratum corneum, but about 15% reaches the dermal layer, provoking the active synthesis of melanin. Rays of the UVA spectrum have a longer wavelength and affect the skin more gently, without causing significant burns and less dangerous oncology. However, they lead to irreversible changes in the connective tissue: "vascular stars" appear, venules expand, collagen and elastin break down, causing the skin to lose elasticity, fine wrinkles and age spots appear.
Types of reactions
When the skin is exposed to ultraviolet rays, phototraumatic, phototoxic, photodynamic and photoallergic reactions may occur.
To date, there is no generally accepted classification of photodermatitis.
According to clinical characteristics, the following are distinguished:
- acute photodermatitis;
- chronic (erythematous, bullous, pruritic-eczematous, atrophic-degenerative);
- professional photodermatoses;
- pigmentation disorder;
- medically and cosmetically provoked;
- photodermatitis of food origin.
Full version of the access article in Ukrainian
This article is part of the special project Prevention of photoaging
