Acute Tropical Ulcer - An Eroding Skin Lesion

Introduction:

Acute tropical ulcers are also known as tropical phagedenic ulcers due to their eroded or nibbled appearance. The ulcer develops into small itchy, or painful lesions on the lower legs or feet. These lesions may rupture suddenly, revealing a deep necrosed region involving the dermis and subcutaneous tissue. A large number of bacteria, including gram-negative organisms, is a peculiar feature of this ulcer.

What Is the Etiology of Acute Tropical Ulcers?

Acute tropical ulcers can be due to several factors:

• Different types of bacteria are present in the lesion. During the early stages, Fusobacterium species (Fusobacterium ulcerans) are always present. Bacillus fusiformis and Treponema vincenti are frequently found during the late stages. Other bacterial species, such as Escherichia coli and Enterococcus, are also detected in some cases.

• Ulcers might result from injury or skin trauma due to insect bites or scratches. Rural laborers are at an increased risk as they do not wear proper protective clothing and footwear.

• Poor hygiene and chronic diseases such as malaria may also increase the risk of the development of an acute tropical ulcer.

What Are the Clinical Features of Acute Tropical Ulcers?

The clinical manifestation of acute tropical ulcers include:

• A small patch that gradually develops into a boil of more than one centimeter rapidly between five to six days, usually on the lower leg.

• When this lesion ruptures, it exudes blood-stained foul-smelling pus.

• At this stage, the epidermal layer of the tissue is destroyed, and tissue damage is visible.

• The ulcer is round or oval, with a clearly defined edge.

• Acute tropical ulcers usually occur on the lower legs. However, it might appear on the arms and thighs.

• Edema and hyperpigmentation are present around the ulcer that can be seen even after the ulcer has healed.

• Usually, growth in ulcers is seen during the first two to three weeks and reaches its maximum size after six weeks.

• Initially, the acute tropical ulcer, the lesion is painful. If the ulcer does not heal, it becomes chronic and is no longer painful.

• If the tropical ulcer is treated immediately in the acute phase, it can heal and may not progress to the chronic ulcerative stage. Sometimes, the lesion heals spontaneously without treatment. However, it might take months or years for the lesion to heal and can form a heavy fibrotic scar.

• Patients may be delirious and severely ill. However, it rarely causes regional lymphadenopathy. Ulcers may penetrate deep into the periosteum of the underlying bone. The ulcers frequently lead to structural and functional dysfunction of the affected region, and sometimes healing is accompanied by scarring. In some cases, acute tropical ulcers can even be present for ten years or more.

How Is the Acute Tropical Ulcer Diagnosed?

1. Acute tropical ulcers can be diagnosed using a skin swab for bacteriology, but it requires unique technology.

2. The rapid onset of the lesion, its peculiar shape, and size also help in diagnosis.

3. It can be diagnosed by excluding other skin infections, such as

• Cutaneous tuberculosis.

• Leishmaniasis.

• Venous stasis.

• Pyoderma gangrenosum.

• Carcinoma.

Laboratory culture is usually predominated by the presence of Fusobacterium and anaerobic bacteria. A proper clinical history and biopsy of the ulcer margin may also help rule out other skin infections.

What Preventive Measures Should Be Taken?

• Acute tropical ulcers usually start with a tiny lesion like an insect bite, a scratch, or a perforated wound. Covering the legs and taking proper care of the lower limbs help to prevent acute tropical ulcers.

• Careful cleaning of minor wounds and proper dressing can prevent the degrading of an ulcer.

• Cleaning the mud from the legs immediately after injury also helps prevent acute tropical ulcers.

What Is the Epidemiology of Acute Tropical Ulcers?

Acute tropical ulcer is usually seen in humid tropical regions of the world like India, Africa, and the Western Pacific region. The ulcer commonly affects children and young adults, particularly those individuals who are exposed to mud or stagnant, contaminated freshwater. Usually, patients report a history of some trauma before the occurrence of the ulcer. In adults, it appears that they occur more commonly in women than in men. Poor health and malnutrition are not risk factors in the initial development of an acute tropical ulcer.

However, health status and nutritional deficiency may hamper the progression of the condition.

Currently, there is a decline in the prevalence of acute tropical ulcers due to increased awareness about environmental and health education, personal hygiene, and the easy availability of antimicrobial therapy.

How Is Acute Tropical Ulcer Treated?

Treatment of skin diseases is standardized in developing countries. It is usually based on the use of simple management strategies that are affordable and easy to administer. As expected for a disease of uncertain etiology, many treatment issues remain unresolved.

• Initially, the administration of oral antibiotics, like Penicillin, Erythromycin, Metronidazole, or Tetracycline, for one week is used to treat the ulcer.

• Successful wound care involves cleaning the wound with clean water, topical antibacterial like Gentian Violet, and routine dressing.

• Painkillers can also be administered in the acute stages of the ulcer.

• Daily cleaning of the wound with clean boiled water should be done.

• The wound should be covered with a clean non-adherent dressing that is changed daily. If the wound exudes a lot, the frequency of the dressing should be adjusted accordingly.

• Maintaining adequate nutrition is also essential, along with antibiotic therapy.

• Apart from the above care, healing the ulcer involves proper rest, the elevation of the affected limb, and local wound care with appropriate compresses.

• In addition, reconstructive surgery may be required in severe chronic cases.

• Skin grafting can also be helpful in cases to ensure that the ulcer does not progress to the chronic stage.

Conclusion

The treatment protocols for acute tropical ulcers are devised to ensure complete recovery of the infection. Complications of this ulcer involve osteomyelitis, septicemia, and the development of squamous cell carcinoma. The untreated cases of acute tropical ulcers lead to a chronic infection involving necrotic slough and involvement of deeper subcutaneous tissues and bone.