Leprosy

The leprosy is a chronic granulomatous disease that primarily affects the nervous system peripheral skin and mucosa. Its clinical manifestations are very varied, which makes it possible to distinguish different forms of disease, each with a different prognosis and sequelae.

It is a historical disease, whose first reference dates from the 6th century BC. C. It has not been possible to establish a place of origin of leprosy, although India has always been one of the countries in which more epidemics have been suffered, being possible that its spread from there to China, Japan, the West and the whole Mediterranean. Currently it is accepted that the Phoenicians extended it to Spain, while the arrival of Europeans and Africans to America after the discovery would be responsible for its extension to this continent. It is more common in tropical countries.

The number of leprosy cases is estimated at around 4-5 million in Africa and Southeast Asia, 200,000 in Europe and the eastern Mediterranean, and 2 million in the western Pacific.

Causes of leprosy

It is an infectious disease whose causative agent is Mycobacterium leprae, a germ belonging to the same family as the bacillus responsible for tuberculosis . It was discovered by Hansen in 1873. To this day, no one has managed to cultivate the germ.

It is a highly contagious disease, although the rate of people who become ill is much lower than that of infected people. Its transmission occurs from person to person. Currently, the possible entry point for the bacillus into the body is still under discussion, although it is probably the skin and mucous membranes of the upper respiratory tract. Possible direct contact is under discussion.

The initial consequences of the entry of the bacillus into the body are not well known. From here, it will be the reaction of the immune system that determines the different pathological processes responsible for the multiple clinical forms that the disease can take, from the asymptomatic to the most aggressive and rapidly evolving ones.

The failure of cellular immunity allows the rapid spread of the bacillus and the involvement of multiple tissues, although it also leads to less damage to the peripheral nerves, since this is mainly due to the intense inflammation produced by the response of lymphocytes to the infection.

If, on the other hand, the immune response is very important, a serious complication of leprosy can occur. It is the so-called leproreaction, due to the production of a large amount of antibodies that give rise to significant inflammatory lesions in multiple organs. In general, people with a strong immune response will have a form of disease limited to a few areas of the skin and peripheral nerves.

Symptoms of leprosy

After infection with the bacillus, most people build immunity and do not have the disease. If the initial immune response is ineffective, the germ multiplies, without producing any symptoms, within the incubation period, which generally ranges from 2 to 4 years, although it can vary from 3 months to 40 years.

The clinical manifestations of the disease are a direct consequence of the immunological and bacteriological status, as well as the lesions that have occurred in the tissues during the incubation period. We will distinguish the following clinical stages or forms:

initial

Symptoms of neurological involvement appear, such as paresthesias or decreased skin sensitivity, more or less persistent, as well as skin lesions, in which the sensitivity has decreased and that may disappear spontaneously or persist for 1 or 2 years.

Tuberculoid leprosy

It is manifested early by a clear spot with decreased sensitivity, well defined. Later, the lesions enlarge and their edges rise, spreading to the periphery as they heal through the center. In the affected areas, the sweat and sebaceous glands, as well as the hair follicles, disappear.

Regarding nervous involvement, it is early and leads to an enlargement of the most superficial nerves, which are palpable through the skin. It can lead to severe pain. Secondary to the nerve involvement, there is atrophy and contracture of the muscles, ulcers and skin wounds that can become infected and, finally, loss of the phalanges. The involvement of the facial nerves ends up producing blindness.

lepromatous leprosy

Skin lesions can be varied (plaques, spots or nodules). Loss of eyebrow tails is common. Later, the skin on the face and forehead thickens and wrinkles (leonine facies) and the earlobes hang down.

There is usually nasal obstruction, epistaxis, difficulty in nasal breathing, hoarseness and laryngitis. The perforation of the septum and nasal collapse give rise to the so-called saddle nose. Other clinical manifestations are ocular involvement, lymphadenopathy and infertility in men.

Borderline leprosy

It gives rise to skin lesions similar to the tuberculoid form, although more numerous and with less well defined limits. The anesthesia is less marked, the earlobes may be thickened, but the nose and eyebrows remain intact.

Leprosy is one of the most important causes of manual disability worldwide.

Diagnosis and treatment of leprosy

Apart from the clinic, the diagnosis is based on the detection of the responsible bacillus in the smears of the skin of the patients. In addition, whenever possible a skin biopsy should be referred to a leprosy pathologist to ensure the diagnosis.

Blood tests do not usually provide relevant data. There are tests for the detection of specific antibodies (serology) against the bacillus that are useful today.

Treatment encompasses various fields of medicine: orthopedic surgery, physical therapy, and ophthalmology, in addition to drug treatment.

The basic pillar of the latter is dapsone. It is a cheap drug that can be administered to pregnant women. Side effects are rare. Resistance to this drug is currently developing. Other drugs such as rifampin or clofazimine can also be used.

How to avoid it?

As previously mentioned, the form of transmission of the leprosy bacillus is not clear, but it is advisable to use masks and gloves when dealing with active leprosy patients, since it is a highly contagious disease.

You should consult your doctor whenever you have alterations in sensitivity (anesthesia, cushing) in any area of ​​your body, although it is exceptional for this disease if you have not traveled to an area endemic for leprosy or have not had contact with sick with leprosy.