Dermographism
The content of the article:
- Kinds
- Causes
- Signs
- Diagnostics
- Dermographism treatment
- Prevention
- Consequences and complications
Dermographism (artificial urticaria) is an abnormal reaction of the skin that occurs as a result of minor mechanical stress and is characterized by the appearance of red or white stripes.
Manifestation of dermographism
Kinds
According to the peculiarities of the skin reaction, several types of dermographism are distinguished:
- White dermographism - the appearance on the skin of pale stripes corresponding to the area of irritation. They usually appear under the influence of light mechanical stress and persist for several minutes.
- Red dermographism. It is characterized by the appearance of hyperemic stripes in the affected area, which may be surrounded by a pale corolla. These bands begin to appear within 15 seconds from the moment of exposure and persist for 1-2 hours.
- Edematous dermographism. Mechanical irritation of the skin causes the appearance of itchy, edematous red stripes on it, around which elements of a rash appear, resembling a rash with urticaria. The edematous form is urticarial dermographism, in which the appearance of stripes is accompanied by the formation of blisters.
- Reflex dermographism. Irritation of the skin with a thin sharp object leads to the formation of wide (up to 6 mm) red stripes on it.
Causes
The causes of dermographism are different. The pathological mechanism of white dermographism is based on angiospasm. This form of skin reaction can be in any person, but it is most clearly manifested in asthenic patients with a predominance of the tone of the sympathetic nervous system.
The main cause of red dermographism is the predominance of the tone of the parasympathetic division of the autonomic nervous system, which is accompanied by the expansion of the blood capillaries in response to mechanical irritation. Also, red dermographism can be a consequence of certain metabolic diseases, such as thyrotoxicosis.
In the pathogenesis of edematous dermographism, the main role belongs to the allergic reaction. Mechanical effect entails a violation of the integrity of the membrane of mast cells of the skin and the release of mediators of allergic reactions from them (histamine, serotonin, heparin, eosinophilic chemotactic factors). Under the influence of these substances, arterioles expand, the permeability of the vascular wall increases, which leads to tissue edema. The exact reasons for the instability of the skin mast cell membranes are unknown. Presumably, some metabolic and genetic factors influence.
Reflex dermographism is essentially a vasomotor reflex, the arc of which passes through the corresponding segments of the spinal cord.
Signs
The phenomenon of dermographism can be observed by holding a blunt-pointed stick over the skin. After 10-20 seconds, a white stripe forms on the skin (white dermographism), which disappears after a few minutes.
If you apply more force when holding the stick, then after 5-15 seconds a red stripe (red dermographism) will appear on the skin, which can persist for up to two hours.
If you hold a blunt stick over the skin, you can observe the phenomenon of dermographism
Significant skin irritation with a blunt stick leads to the manifestation of edematous dermographism. In this case, initially, a red stripe appears in the area of skin irritation. After 1-2 minutes, it turns white, swells and rises above the skin level.
With an increase in the permeability of the vascular wall, even mild skin irritation (for example, a seam of clothing or a belt) leads to the development of urticarial dermographism, which is characterized by the formation of itchy blisters.
Reflex dermographism can be induced by passing a sharp needle over the skin. After 10-30 seconds from the moment of exposure, a wide strip (up to 5-6 mm) of bright red color appears on the skin. Gradually it turns pale and disappears after a few minutes.
Diagnostics
The study of the features of dermographism is of great diagnostic value. So, the study of white and red dermographism allows you to assess the reactivity of the capillaries. It should be borne in mind that many factors influence their tone (in particular, ambient temperature, body temperature). Therefore, as a diagnostic symptom, dermographism has value only if it is significantly increased or absent.
Increased manifestations of dermographism are usually observed in patients with meningitis, thyrotoxicosis, autonomic neurosis. With severe intoxication of the nervous system, general depletion of the body, the phenomena of dermographism, on the contrary, are poorly expressed, and sometimes they cannot be caused at all.
The absence of reflex dermographism in a certain area of the dermis allows us to determine the localization of the lesion in the spinal cord.
The phenomena of dermographism can occur against the background of a number of internal diseases, therefore, patients with this symptom are shown consultations of narrow specialists (neurologist, endocrinologist, immunologist, helminthologist, etc.).
Dermographism treatment
The need for the treatment of dermographism arises only in the case of intense skin manifestations, accompanied by itching. To stop them, the patient is prescribed antihistamines.
For patients with urticarial dermographism, therapy with ketotifen is indicated for 2-3 months. Against its background, the mast cell membranes stabilize, as a result of which abnormal skin reactions in response to irritation occur much less frequently.
Antihistamines are prescribed for dermographism, accompanied by intense skin manifestations and itching
In some cases, ultraviolet irradiation of the skin has a good, but short-term effect.
To reduce puffiness and itching, lotions from infusions of medicinal plants (oak bark, chamomile, sage) allow.
With the identification and treatment of provoking diseases, it is possible to achieve a long-term remission of dermographism, and in some cases, complete recovery.
Prevention
Since the causes of dermographism are diverse, and some are not fully understood, primary prevention measures have not been developed.
Secondary prevention consists in measures aimed at preventing recurrence of severe skin manifestations. Patients are advised to avoid compression or friction of the skin, to give preference to loose-fitting clothing, sewn from soft tissues.
Consequences and complications
If dermographism is accompanied by severe itching, the patient intensively scratches the skin, which is fraught with infection and the development of an inflammatory process.
Elena Minkina Doctor anesthesiologist-resuscitator About the author
Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.
Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
