By a simple dermatitis is acute and solar dermatitis (dermatitis Solaris) in subjects with normal sensitivity to ultraviolet rays, which develops after prolonged exposure to the sun. For solar dermatitis is characterized by the latent period, whose duration is determined by the intensity of insolation. The clinical picture is diverse – from mild erythema to severe burns accompanied by general reactions. With heightened sensitivity to ultraviolet rays (usually in people with liver disease, a violation of the porphyrin metabolism), even a short exposure to sunlight, especially early spring, causes an inflammatory reaction that can be extremely persistent, clinically polymorphic (erythema, papules, vesicular rash, desquamation, pigmentation) in some cases, to some extent reminiscent of eczema. Develop allergic dermatitis after repeated contact with irritants, possessing sensitizing properties. An indispensable condition for the development of allergic dermatitis is sensitization, so inflammatory changes in repeated contact with allergens develop over time (from several days to 2 – 3 weeks) after the first contact with this or that substance-sensitizer.
Clinically, allergic dermatitis, similar to artefitsialnymi, but in the early stages of the process is not limited to the place of contact with the allergen, but extends to distant parts of the body. Eruptions more polymorphic, possible (especially with repeated outbreaks) and Moisture vesiculation resembling eczema. The boundaries of lesions less sharp than in the simple cases of dermatitis. Allergic dermatitis regressed considerably slower frequent relapses in contact with a substance that caused the disease. If atopic dermatitis often recurs, then the clinical picture is very similar to eczema, and often transforms into her. Allergic is the bulk of medications, occupational dermatitis, and dermatitis caused by increased sensitivity to the plants. Medicinal dermatitis (dermatitis medicamentosa) can result from external Drug effects (contact dermatitis medication) or the introduction of drugs by mouth or parenterally (toksidermii). In the latter case, the inflammatory response is more significant, the process is more commonly, the rash often located symmetrically.