Cutaneous leishmaniasis

Infectious disease caused by a Leishmania protozoan. When symptoms appear on the skin, it is known as cutaneous leishmaniasis.

It is more common in southern European countries, Asia, Africa, Mexico, Central and South America.

It is transmitted by sand flies, a mosquito that usually bites dogs and/or rodents, and eventually humans.

One of the first symptoms is usually a lump on the skin that appears weeks or even months after the bite. Inside the lump is a collection of parasites and white cells that fight to keep the infection under control.

Over time, the lump will grow to become an ulcer-like open lesion that will eventually ooze and form a scab. At the same time, new lumps appear in the area surrounding the original lump. The ulcers are usually painless and don't cause any other symptoms unless they become infected with some kind of bacteria. In this case, there may be pain, redness of the skin and fever.

The diagnosis is clinically suspected when the lump appears on the skin and when a possible mosquito bite is detected in the area of the lesion. To confirm the diagnosis, a sample culture of the ulcer is needed to isolate the Leishmania bacterium and identify its genetic material.

Treatment depends on the size of the ulcer. If it is small, it can be treated with cryotherapy, paromomycin-based cream and/or direct injection of sodium stibogluconate. For larger or multiple ulcers, antileishmanial drugs such as liposomal amphotericin B or miltefosine are used.

In the case of bacterial superinfection, standard antibiotics for skin infections should be used.

Prevention of mosquito bites is recommended with repellents, appropriate clothing and mosquito nets, and avoidance of outdoor activities after dusk when mosquitoes are most active.