OVERVIEW
Melioidosis is a rare hereditary disorder of amino acid metabolism. The patient’s liver is deficient in the enzyme melanuric acid oxidase, which results in large amounts of unoxidized melanuric acid being excreted in the urine and deposited in various tissues and organs of the body. If the black uric acid is deposited in the joint tissues, it causes joint diseases related to melioidosis, including melioidosis arthritis.
Causes
Melioidosis is a rare genetic disorder of amino acid metabolism. There is usually a family history of the disease, and the incidence of the disease varies between males and females, about 2:1. Bone and joint changes usually affect the spine first, followed by the knees, shoulders, and hips.
Symptoms
Usually, there is a family history of this disease, and the incidence of male and female is different, about 2:1. After birth, there are no other symptoms, except for placing urine oxidized black and brown, which makes the diaper stained black. Until 20 or 30 years of age due to excessive deposition of black uric acid, only to produce a series of symptoms. The main symptom is the whole body skin, sclera, cornea pigmentation is tawny, ear, nose, cartilage can become blue, the edge of the tympanic membrane is gray-black, hearing is often reduced. Uric acid deposition in the aortic valve and mitral valve, the valve hardens and a murmur appears. Black prostate stones are common in male patients.
Bone and joint changes usually erode the spine first, followed by the knees, shoulders, and hips. The incidence of spondylolisthesis is 10% to 15%, with more men than women. The main manifestations are low back pain, loss of lumbar lordosis, mild hunchback deformity, and posture similar to ankylosing spondylitis. Progressive stiffness of the spine, degeneration, narrowing, calcification of the intervertebral discs, marginal osteophyte formation, involvement of the intervertebral ligaments, and even finally bony ankylosis. The joint tissues of the limbs also produce degenerative changes due to pigmentation, loss of elasticity of the articular cartilage, fibrosis and hardness of the synovium thickening, erosion and cystic changes of the subchondral bone of the joints, with dense and sclerotic bone as well as formation of bony encumbrances, which can lead to joint ankylosis. The synovial membrane of the joint is villous and hyperpigmented, and there are pigmented cartilage debris in the joint fluid.
Examination
1. Urine black acid test
Urine becomes black after standing or darkening, and turns brown with spotting reagent.
2.X-ray examination
There are prominent features in performance, and some patients’ performance precedes clinical symptoms. x-ray shows osteoporosis of spine, calcification and narrowing of intervertebral disc, narrowing of joint space of knee, shoulder and hip, sclerosis of subchondral bone, formation of cystic cavities, calcification of meniscus, free body of osteochondral bone, borderline osteochondral and calcification of tendon. Unlike rheumatoid arthritis, xanthomatous disease usually does not involve the small joints of the hands and feet.
Diagnosis
Diagnosis can be made on the basis of clinical manifestations, imaging examination and urinary black acid examination.
1. Imaging examination usually shows prominent features, such as osteoporosis of the spine, calcification and narrowing of intervertebral discs, narrowing of the joint space of knees, shoulders and hips, sclerosis of subchondral bone, formation of cystic cavities, calcification of meniscus, osteochondral free bodies, marginal bone cumbersomening and calcification of tendons.
2. Urine black acid test is also one of the important diagnostic criteria, the urine becomes black after alkalinization or standing, and becomes brown with spotting reagent.
Treatment
There is no special effective treatment for this disease. Degenerative changes are the same as in proliferative arthritis. The patient should perform appropriate activities, but should not increase joint weight bearing. Arthroplasty is an option if the patient has joint pain and severe motor dysfunction.
Prognosis
Xanthogranulomatosis is chronic and progressive, with changes in urine color visible as early as a few days after birth; skin discoloration at 20-30 years of age; joint symptoms and xanthogranulomatosis-related arthropathy at 30-40 years of age; and complications such as kidney disease at around 50 years of age. Arthropathy can be disabling, survival can be long, and cause of death is mostly cardiovascular disease and uremia.