Infectious diseases

syndrome, which one can use for the differential diagnosis. The differential diagnosis of a fever needs to be done to distinguish it from the body temperature rising of another nature (thermal shock, hyperthyroidism).

The second component which is not less important for the diagnosis and differential diagnosis of the infectious diseases is a rash on the skin -exanthema. It is because the rashes are a symptom of many infectious diseases, besides, they are well visible, quite often catch one's eye even at the first examination of the patient.

There are exanthemas, characteristic of this or that infectious disease and they are an obligatory component of a clinical symptomatology of this or that infectious disease.

The expressiveness and nature of exanthemas can be miscellaneous and are not always observed in other infectious diseases. Due to this factor their presence or absence in different infectious diseases essentially differs.

The exanthemas in infectious diseases are rather diverse. They differ in nature of different elements of an eruption, localization, terms of appearance, stages of a rash, the dynamics of development of separate elements, etc. All these features are taken into consideration while making a differential diagnosis. In the diagnostics process the legible definition of separate elements of an eruption and unified comprehension of the terms are very important. Dermatologists and infectionists do not always define some elements of an eruption in the same way. The following nomenclature is generally accepted in infectious diseases.

Roseola - is a small spot (diameter 2-5 mm) of pink, red or purple-red color, more often with a spherical form. It is formed as a result of a local vasodilatation of a papillary layer of skin. The roseola disappears when pressing the eruption area with a transparent glass-spreading rod or when stretching a skin and comes up again after the stopping of pressure (stretching) that is the main distinctive feature of it.

The so-called punctate rash is close to roseola. It consists of a set of shallow (in a diameter of about 1 mm) elements of the red color. At stretching the skin these elements, as well as roseolas, disappear. Each element rises a little above the level of the skin that stipulates a special "velvety" of the skin at the eruption area.

The macule (macula) represents an element of the eruption similar to the roseola, but larger (5-20 mm), it does not stick above the level of the skin, its color is the same as roseola's. The development of the spot, as well as in case of roseola, is-based on vasodilatation. The form of maculae can be oval, spherical or more often small or with festoon edges. Unlike the dermatologists the infectionists distinguish -spot eruption, in which the elements of an eruption vary in diameter from 5 up to 10 mm, and "large-spot eruption" with the elements' diameter of 11-20 mm. This distinction has a differential - diagnostic value. For example, in a patient with rubella there is a small-spot eruption, and in a patients with measles - a large-spot one.

Papule (papula) - a superficial formation without a cavity, rising above the level of the skin. It has a mild or dense consistence, the reverse development ends without the formation of a scar. There are inflammatory and noninflammatory

Date: 2014-12-21; view: 932