leprosy uveitis
Introduction
Introduction to leprosy uveitis Leprosy is a chronic granulomatous disease caused by M. leprae, also known as Hansen's disease, which mainly affects the skin, peripheral nerves, mucous membranes and ocular tissues. Leprosy uveitis mainly occurs in lepromatous leprosy, mainly causing iridocyclitis, which can be manifested as acute iridocyclitis, chronic iridocyclitis, miliary iris leprosy nodules, and large iris leprosy nodules . Posterior segmental lesions are rare, occasionally causing choroiditis, non-specific disseminated peripheral choroiditis, and retinal pigment epithelial proliferation. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: contact infection Complications: glaucoma, cataract, iridocyclitis
Cause
Causes of leprosy uveitis
The disease is due to uveitis caused by direct invasion of M. leprae.
(1) Causes of the disease
M. leprae is a kind of bacteria growing in cells. It is short rod-shaped, (0.21×3) m(0.5×8) m. Human is the main host of M. leprae. Other animals such as baboons, chimpanzees, monkeys, etc. Can be infected.
(two) pathogenesis
After invasive into the body, M. leprae can directly cause tissue damage, and can cause different tissue damage through immune reaction. If the patient has strong immunity to M. leprae, it will only show subclinical infection after infection; if the patient's cellular immune function is normal Tuberculosis-like leprosy can occur, and less than 10% of these patients have antibodies to the leprosy antigen; if the patient's cellular immune function is reduced, it causes diffuse leprosy nodules (tumor type leprosy), and most patients have anti-protease antigens. The level of specific antibodies is elevated, and autoantibodies such as cryoglobulin, rheumatoid factor, anti-thyroglobulin antibody, anti-nuclear antibody, anti-smooth muscle antibody, anti-myelin antibody, etc. may occur, and these autoantibodies have no protective effect. Instead, it is possible to participate in the disease through antigen-antibody immune complexes.
Prevention
Leprosy uveitis prevention
To control and eliminate leprosy, we must adhere to the principle of prevention first, implement the principle of active prevention and control, control infection, and implement the practice of investigating, segregating, and treating, discovering and controlling infectious diseases, and cutting off infection. Ways, giving regular drug treatment, while improving the immunity of the surrounding natural population, can effectively control infection and eliminate leprosy. In view of the current prevention of leprosy, lack of effective preventive vaccines and ideal preventive drugs, In the method, various methods should be used to detect patients early, and the patients should be given timely combined regular chemical treatments, and close contacts of children in the endemic areas, family members, and polio and tuberculin reactions. , can be given BCG vaccination, or given effective chemotherapy for preventive treatment.
Complication
Leprosy uveitis complications Complications glaucoma cataract iridocyclitis
In patients with chronic iridocyclitis, intraocular pressure is usually reduced, but secondary glaucoma can occur in a small number of patients; cataract is a common complication, in addition to iridocyclitis, it may also increase with local phenylhydrazine concentration. Highly relevant.
Symptom
Leprosy uveal inflammation symptoms Common symptoms Scleral outer layer inflammation valgus keratitis Muscle atrophy Photophobia eye pain Pain sensory disorder Tears movement dysfunction
Leprosy uveal inflammation
Uveitis mainly occurs in lepromatous leprosy, with an incidence of 0.5% to 23.8%. Mainly caused by iridocyclitis, can be expressed as acute iridocyclitis, chronic iridocyclitis, miliary iris leprosy nodules and large iris leprosy nodules. Posterior segmental lesions are rare, occasionally causing choroiditis, non-specific disseminated peripheral choroiditis, and retinal pigment epithelial proliferation.
1 acute iridocyclitis: is a common type, non-granulomatous inflammation, usually bilateral involvement. Typically manifested as sudden onset, redness, eye pain, photophobia, tearing, blurred vision or decreased vision. Examination of visible ciliary congestion, KP, obvious anterior chamber flash and aqueous inflammatory cells, severe cases may occur A large amount of fibrinous exudation or anterior chamber empyema can cause complications such as posterior iris adhesion, secondary glaucoma and anterior chamber hemorrhage.
2 Chronic iridocyclitis: occurs in various types of leprosy, granulomatous or non-granulomatous inflammation. Patients usually have no obvious symptoms, no ciliary congestion, examination found that small KP or sheep fat KP, mild anterior chamber flash and a small amount of aqueous inflammatory cells, easy to cause iris atrophy, post-iris adhesions or even pupillary atresia. Iris sympathetic involvement can cause pupils to become smaller, and the resulting cataract can lead to severe vision loss.
3 Miliary iris leprosy nodules: also known as "iris pearls", characterized by small flashing white lesions formed by leprosy accumulated in monocytes. Usually occurs within 1 to 2 years after iridocyclitis, this "iris pearl" is mainly distributed at the edge of the pupil, showing the appearance of a necklace, which can fall into the aqueous humor.
4 large iris leprosy nodules: the incidence is lower than the "iris pearl", showing yellow-white lobulated pleomorphic nodules, may be associated with significant anterior chamber inflammation.
Other eye symptoms of leprosy
1, scleritis and scleral inflammation: focal leprosy nodules can cause nodular scleritis and scleral inflammation; immune response to M. leprae can cause diffuse scleral inflammation through type III allergic reactions or Diffuse scleritis. They are often accompanied by keratitis or iridocyclitis, and repeated and long-term scleral inflammation can cause scleral necrosis, scleral fusion, and scleral staphyloma.
2, other eye lesions: leprosy can cause eyebrows and eyelash loss, rabbit eyes, trichiasis, valgus valgus, subconjunctival fibrosis, corneal nerve thickening (beaded), exposed keratitis, punctate cornea Inflammation, interstitial keratitis, corneal vasospasm with tiny leprosy nodules, etc.
Leprosy systemic symptoms
The incubation period of 3 months to 10 years (usually 2 to 5 years) after the systemic manifestation of leprosy infection occurs. Although different types of leprosy have different clinical manifestations, the basic lesions are skin lesions and peripheral neuropathy, and can also invade mucosa, lymph nodes and ocular tissues. A small number of patients have lesions such as testis, ovary, liver, spleen and bone tissue.
(1) Tuberculosis-like leprosy: Skin lesions are usually rare, manifested as low-pigmented macules or plaques with clear boundaries, often with sensory disturbances of the skin and large peripheral nerves. It is difficult to find the leprosy bacterium on the skin smear, but the leprosy skin test is strongly positive.
(2) Boundary type tuberculosis type leprosy: skin lesions are similar to tuberculous type leprosy, but the number is large, and peripheral nerves are easily affected. Occasionally, the smear can be found in the skin smear.
(3) Intermediate boundary type leprosy: There are a variety of skin lesions, and the number is large, and it is not easy to have peripheral nerve involvement. M. leprae was observed on skin smears, but the leprosy skin test was generally negative.
(4) Boundary type of metastatic leprosy: manifested as multiple rash, papules, nodules or plaques, the boundaries are often unclear, peripheral nerve damage is extensive, can cause sensory and motor dysfunction. Leprosy is usually seen on the skin smear, and the leprosy skin test is negative.
(5) Tumor-type leprosy: manifested as a variety of skin lesions, central uplift, blurred borders, eyebrows shedding, facial skin thickening, saddle-shaped nasal deformity, nodules at the ear and eyebrows, thickening of the nerve trunk, appearance around Neuropathy, causing muscle atrophy and contracture. A skin smear test showed a strong positive for M. leprae and a negative skin test for leprosy.
Examine
Examination of leprosy uveitis
The detection of specific antibody levels of anti-M. leprae antigens in patients has important reference value for the diagnosis, and can also measure cryoglobulin, rheumatoid factor, anti-thyroglobulin antibody, anti-nuclear antibody, anti-smooth muscle antibody, anti-myelamine The level of autoantibodies such as sex protein antibodies clarifies the extent of the lesion.
The leprosy test can determine whether the human body has immunity against M. leprae, and the intensity of its late reaction is proportional to the body's resistance to M. leprae.
Through lymph node biopsy, it was found that the lymph nodes of patients with cancerous leprosy were obviously enlarged, the paracortex lacked lymphocytes, and the tissue cells-macrophages infiltrated. The cells contained a large number of leprosy, and the number and area of germinal centers increased. Its margin is surrounded by bone marrow-derived lymphocytes, and there are a large number of plasma cells in the cortex, medullary junction and myelin.
Diagnosis
Diagnosis and diagnosis of leprosy uveitis
diagnosis
The disease is diagnosed with clinical symptoms and examinations such as typical symptoms of leprosy, ocular manifestations, and leprosy skin test results.
Differential diagnosis
Acute iridocyclitis caused by leprosy is not characteristic, so it should be associated with all diseases that cause acute anterior uveitis such as HLA-B27 antigen, uveitis associated with ankylosing spondylitis, and acute anterior uveitis , Reiter syndrome associated with acute anterior uveitis, idiopathic acute anterior uveitis, etc.; the chronic anterior uveitis caused by it should be associated with tuberculosis, syphilis, sarcoma, Lyme disease, herpes simplex virus Identification of anterior uveitis caused by or associated with herpes zoster virus.
