Loaosa

Loaosis /Calabar tumor/ is a chronic helminthosis, the characteristic feature of which is the migration of sexually mature parasites into the tissues of the body, which causes the development of the so-called calabar tumors.

The disease is spread only in the countries of West and Central Africa. People of any gender and age are prone to it, however, they most often affect men of mature age with black skin. According to the available data, about 12-13 million people suffer from this disease.

What are the causes?

Calabary tumor is caused by the roundworm Loa loa, which is dioecious. Adult females reach a length of 50-70 mm, and males – 25-35 mm.

The diameter of these worms is about 0.25 mm. Sexually mature individuals inhabit the subcutaneous fatty tissue, the disease belongs to the group of filariasis.

What are the symptoms?

There are significant differences in the course of the disease in people who live in endemic outbreaks and those who arrive there from other parts of the world, that is, immigrants.

In part of the indigenous population, this type of filariasis occurs asymptomatically with microfilaremias. In such cases, the disease is detected only after the migration of sexually mature parasites under the conjunctiva.

The incubation period is usually several years, but sometimes it is about 4 months. The disease begins with allergic manifestations. A rash characteristic of urticaria appears on the patient’s skin, the body temperature rises to subfebrile values.

Those infected with worms complain of pain in the limbs and paresthesias. The subsequent migration of the parasites into the subcutaneous tissues causes itching and burning.

When Loa loa roundworms penetrate under the conjunctiva of the eyes, conjunctivitis develops with swelling of the eyelids, and this process is accompanied by strong painful sensations.

When the parasite enters the urethra, pains appear, which are dependent on urination.

This parasitic disease is characterized by sudden manifestations in limited areas of the body of painless swellings, which dissipate usually within 3 days, rarely lasting several weeks.

The skin in the area of ​​swelling is pale or, on the contrary, hyperemic, that is, red and swollen. Edemas can form on any part of the body, but most often they form on the limbs. A more frequent appearance of such formations is observed in the summer, when the ambient temperatures are very high.

Cases of the development of hydrocele in men have also been described, as well as numerous intramuscular abscesses, which occur as a result of the occurrence of secondary infection in the areas where the adult parasites have died.

There are also data on the development of symptoms of encephalitis when roundworms enter the central nervous system. Expressed eosinophilia and secondary anemia are found in the peripheral blood.

Treatment of loaosis

Diethylcarbamazine is applied, but the doses are determined individually by the attending physician. Most often, however, in this disease, more than the permissible 6 mg per kg, about 8-10 mg, are applied. per kg daily for a period of 21 days.

Several courses of treatment are necessary. The preparation affects both adult roundworms and their larvae.

In case of a large amount of microfilariae, the treatment may be accompanied by increased allergic manifestations, side reactions, including those from the central nervous system.

In case of severe invasion, it is recommended to start the treatment with glucocorticoids – prednisone, 40-60 mg/day, internally and small doses of diethylcarbamazine – 0.5 mg/kg/day.