Trophic ulcers: causes, symptoms, diagnosis, treatment

Tropical ulcer is a collective term used to designate ulcers that are different in origin and clinical picture, but have in common the climatic and geographical factors necessary for their occurrence and development in tropical and subtropical countries. At present, of all the variety of tropical ulcers, the most clinically independent are primarily tropical ulcer proper, tropicoloid ulcer, desert ulcer and coral ulcer.

Tropical ulcer is a persistent and sluggish ulcerative process with a dominant localization on the skin in the ankle joint area and, less often, the lower third of the leg, which occurs more often in children, young and middle-aged men living in tropical and subtropical climates. As synonyms, tropical ulcer is sometimes called phagedenetic, scabby, jungle, Madagascar, etc.

Epidemiology of tropical ulcers

Tropical ulcer disease is found in most countries with hot, tropical climates. In South America, these are Brazil, Guyana, Columbia, Ecuador, Argentina, Chile, etc. On the African continent, tropical ulcers are found with relatively high frequency in almost all countries, especially in the east and south of the continent. Many patients with tropical ulcers are registered in India, Sri Lanka, Nepal, less often in southern China and Indonesia. Rare cases are observed in Iran, Turkey, and other countries of the Middle East.

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Causes of tropical ulcers

Despite numerous studies, the issues of the etiopathogenesis of tropical phagedenetic ulcers remain unclear in many respects. Today, there is a point of view that the causes of tropical ulcers are a mixed streptococcal-staphylococcal infection with the obligatory presence of fusospirillum in this association. English dermatologists have proposed a theory of the etiopathogenesis of tropical ulcers, described by four letters F: foot, fusobacteria, filth, friction. This means predominantly foot damage, the constant presence of fusobacteria in the mixed flora of the ulcer, natural bacterial contamination of the external environment of the tropics and a naturally high risk of injury to the skin of the lower extremities due to traditionally open shoes or the absence of them.

A decrease in the protective properties and reactivity of the body as a result of the presence of certain concomitant diseases, such as malaria, yaws, dysentery, helminthiasis and other tropical infections and parasitoses, predisposes to tropical ulcers. Tropical ulcers are often observed in people suffering from alimentary dystrophies, as well as hypo- and avitaminosis.

The importance of vitamin deficiency in the pathogenesis of tropical ulcers is evidenced by the dependence of their frequency of occurrence on the time of year, i.e. seasonality. It is known that tropical ulcers occur more often in the spring, when the diet of the population of endemic zones is depleted of vitamins. Closer to autumn, when the diet becomes more varied and enriched, the number of cases of the disease decreases.

Other factors that contribute to the development of tropical ulcers include poor personal hygiene, late treatment of skin injuries, including bites from various insects, pricks from thorny and especially poisonous plants, contamination with soil, etc.

There is also a persistent and well-founded belief that tropical ulcers are a disease of the poor, which is a reflection of the low socio-economic level of developing countries in the third world, most of which belong to tropical and subtropical regions.

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Symptoms of tropical ulcer

Tropical ulcers are most often observed in adolescents and young men, less often - at the age of up to 40 years. This is explained, first of all, by the most frequent exposure of this contingent to injuries of the skin of the lower extremities. Usually tropical ulcers are registered as individual observations, however, cases of small epidemics have been described, in particular, among prisoners of war, tea pickers, jungle guides, etc.

In the vast majority of cases, the typical localization of tropical ulcers is the lower extremities, especially the ankle area and the lower third of the shin, i.e. places most often exposed to injury and contamination in tropical conditions, as well as bites of various insects. As atypical cases, tropical ulcers can be localized on the skin of the upper extremities and other areas of the body.

In most patients, tropical ulcers are single and predominantly unilateral. In the mechanism of rare cases of multiple ulcers, the phenomenon of autoinoculation may apparently occur.

Symptoms of a tropical ulcer often begin acutely: with the formation of a pea-sized vesicle or phlyctena, surrounded by a clearly visible acute inflammatory rim. When palpating, a limited compaction is often determined at the base of the phlyctena. Often, the element causes pain to patients from the very beginning, which intensifies even with the lightest touch. Quite quickly, already on the second day, the phlyctena cover breaks through with the release of a small amount of purulent serous-bloody fluid. The erosion that forms after this, which in a short time turns into an ulcer, is usually superficial at first, has round or oval outlines, a dirty-grayish bottom and clear, somewhat undermined edges. In the process of further evolution, the ulcer can slowly grow both in depth and along the periphery.

Soon, necrotic masses of ash-gray color, sometimes with some yellowish-green tint, begin to form in the center of the ulcer. The scab is usually doughy-soft, emits an unpleasant odor, and when it is rejected, soft pink-gray granulations are found at the bottom of the ulcer against the background of purulent-necrotic tissue decay. Often, despite the development of granulation under the scab (especially in the center of the ulcers), the process of soft tissue decay in the ulcer area not only does not stop, but on the contrary, continues, capturing the deep subcutaneous layers.

A very typical symptom of tropical ulcers is the so-called phenomenon of gravity. It is expressed in the fact that the growth of the ulcer along the periphery goes mainly in the direction of gravity, i.e. with a predominantly vertical position, the ulcer "crawls" downwards, toward the foot.

It should be noted that, despite the relatively acute clinical course of the disease, especially pronounced at the beginning of the development of the pathological process, the reaction of the lymphatic system is usually very weak, so, in particular, regional adenitis is extremely rare. Any pronounced disturbances in the general condition of patients are also atypical. In the absence of treatment, the disease lasts for an indefinitely long time - many months and even years. Successful treatment of a tropical ulcer leads to its disappearance, less often the process ends on its own with the formation of a smooth scar of various sizes and outlines. More or less typical is some depression of the scar, especially in the center, and the presence of a tissue paper sign on its usually hypopigmented background. The peripheral zone of the scar, on the contrary, appears somewhat hyperpigmented.

In a significant number of cases, especially among residents of the African continent, prone to “keloid diathesis”, one of the features of the functional state of their body is that scars can undergo keloidization.

The most common atypical forms of tropical ulcers include the so-called hypertrophic tropical ulcer. It is characterized by the fact that as a result of vigorous vegetation developing at the bottom of the ulcer, warty growths begin to clearly protrude above the general level of the skin, resembling an almost continuous and uneven conglomerate.

Rarely, especially in patients exhausted by certain general somatic diseases, the ulcer can be fulminant in its course from the very beginning, proceed malignantly and lead to deep necrosis. In such cases, general phenomena are observed in the form of an increase in temperature to 38-39 C, as well as leukocytosis and an increase in ESR. The possibility of sepsis development is not excluded.

Diagnosis of tropical ulcer

Tropical ulcers are most often differentiated from varicose and other trophic ulcers. It is important to remember that varicose ulcers usually develop against the background of a general varicose symptom complex, are observed much more often in women, especially in the elderly, and are localized, as a rule, in the lower third of the shin. However, for tropical conditions, differential diagnostics of tropical ulcers with Buruli ulcer, which is also endemic for these regions of the world, may be more relevant. Buruli ulcer is characterized by multiple skin lesions, a variety of localizations, susceptibility to it in all age groups, a more pronounced "creeping" and penetrating nature with the formation of rough scars.

The diagnosis of "tropical ulcer" is established exclusively on the basis of a typical clinical picture. Macroscopic and cultural diagnostic methods are of lesser importance, since it is possible to detect a wide variety of pathogens, sometimes of a secondary nature.

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Treatment of tropical ulcers

Systemic treatment of tropical ulcers usually involves the use of broad-spectrum antibiotics, often in the form of combined sequential or rotational therapy. This technique is dictated by the association of microbes underlying the etiopathogenesis of the disease, and whose participants often have different sensitivity and resistance to individual antibiotics. Sulfonamides are also used internally and in the form of powders. Local treatment of tropical ulcers involves irrigation of the ulcer with various disinfectant solutions, the use of antiseptic and anti-inflammatory ointments, including corticosteroids, preferably in combination with antibiotics. If indicated, surgical intervention is used - removal of foci of necrosis (excision within healthy tissue) with subsequent application of a tiled bandage from strips of adhesive tape. In extreme advanced cases, especially with extensive gangrenous decay and deterioration of the general condition, amputation of the limb is indicated.

How is tropical ulcer prevented?

Tropical ulcers can be prevented by maintaining personal hygiene, timely treatment of microtraumas of the skin of the lower extremities (wearing shoes). Active and early treatment of all common skin lesions is necessary.

The prognosis of tropical ulcers is usually favorable and largely depends on the general condition of the body and its reactivity. In some cases, the process can lead to deep and severe cicatricial contractures and disability; decreased work capacity can also be observed as a result of the development of ankylosis of the ankle joint.