Lepra (leprosy): diagnosis
Last reviewed: 23.04.2024
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Diagnosis of leprosy is based on the detection of dermatological and neurological symptoms of the disease and evaluation of the results of functional and laboratory studies. Great importance is attached to anamnesis, living in an endemic zone, contact with leprosy patients. Since the patient has a long (for years) no subjective sensation of the disease (absence of an increase in temperature, pain and itching in the area of rashes), for timely detection it is necessary to examine the patient in good light. It is necessary: to conduct a neurological examination to detect thickened nerve trunks and cutaneous nerve branches (especially in the area of rashes on the skin).
A great diagnostic value is the Minor test for assessing sweating. The test area of the skin is smeared with a solution of iodine and sprinkled with a thin layer of starch. Then the patient is sweated (hot drink, dry air bath, injection of 0.2 ml of a 1% solution of pilocarpine hydrochloride). In those places where there is no sweating, there will be no black color from the iodine compound with starch in the presence of moisture.
The histamine test also has diagnostic significance. Due to the violation of peripheral neuroregulation with leprosy, the usual three-component skin reaction to histamine in the form of redness, swelling and itching may be either partial or completely absent.
The index of immunological reactivity of an organism with respect to a leprosy infection is the lepromine test or the Mitsuda reaction. Lepromin is a specially prepared suspension in an isotonic solution of mycobacterium leprosy, taken from fresh leproms of an untreated patient. With intradermal administration of 0.1 ml of lepromine, the result is read after 3 weeks. In healthy people and in patients with tuberculoid leprosy and border tuberculoid, the Mitsuda reaction is positive, and with a decrease or lack of resistance - negative.
The standard of leprosy diagnosis includes:
- Examination of the entire skin, as well as mucous membranes of the upper respiratory tract;
- palpation of nerve trunks and cutaneous branches of nerves;
- Examination of limbs for detection of amyotrophy and contractures:
- setting functional tests in the foci of skin lesions (detection of violations of various types of skin sensitivity, a sweating test, a test with nicotinic acid, etc.):
- bacterioscopic study, which allows to detect acid-fast mycobacteria in smears from skin scarps;
- pathohistological examination of skin taken from the edge of the lesion focus, with Tsiol-Nielsen coloring for the detection of M. Leprae.
[Indications for consultation of other specialists
Since leprosy, in addition to skin rashes, it is possible to detect neurologic and amyotrophic lesions, trophic ulcers and osteomyelitis. Lesions of the eyes and respiratory organs, patients are shown consultations of a dermatologist, neuropathologist, surgeon, ophthalmologist, otorhinolaryngologist.
Patients with lepromatous type of leprosy, as well as patients with borderline-lepromatous and borderline forms of leprosy, related to bacterioviruses (open forms), must be hospitalized for epidemiological reasons in anti-prostitution facilities. It is shown that after 3-6 months of active treatment they cease to release bacteria into the environment. Hospitalization is also subject to patients with any other forms of lepra in the stage of exacerbation of the process (reactive states). Patients with tuberculoid forms of leprosy after diagnosis can undergo outpatient treatment (the issue of this and the decision of the transfer to dispensary observation is decided by the commission of doctors of the anti-prostitution facility). Patients must comply with the prescribed individual epidemic regime; There are no other requirements for the regime. The diet should be rich in proteins, contain a small amount of fat.
Differential diagnosis of leprosy
Differential diagnosis of leprosy is carried out with many diseases of the skin and the peripheral nervous system: tubercular syphilis, syphilitic gum, toxidermia, multiforme exudative erythema, red planar lichen, skin tuberculosis, sarcoidosis, mushroom mycosis, reticulosis, leishmaniasis. Erythema nodosum, trophic and perforated ulcers of feet of various etiologies, etc. The tuberculoid type of leprosy is indicated by the nature of the eruptions and the violation of surface types of sensitivity in them (sometimes the identification of single M. Leprae in histological study). A verifying symptom in the lepromatous type of leprosy, in addition to clinical symptoms, is the detection of a large number of M. Leprae.