A 45-year-old female with a chronic back pain
A 45-year-old female presented with a 10-year history of low back pain, difficulty in bending, restriction in back movements, scoliosis, early morning stiffness of the back that improved with activity, and pain in both knee joints without swelling. The patient had a family history of similar complaints and affected family members also demonstrated back pain.
1 / 7
What of the following is the least likely diagnosis for the patient's condition?
The presentation of back pain is very rare in rheumatoid arthritis, and spinal involvement occurs very late in the course of the disease. The patient's symptoms and family history are more suggestive of conditions other than rheumatoid arthritis, making it the least likely diagnosis in this case.
Examination of the spine showed kyphoscoliosis with normal spinal mobility. X-ray of pelvis showed normal sacroiliac joint (Fig. 1).
Fig. 1: X-ray showing pelvis with normal sacroiliac joint
2 / 7
What of the following diagnosis can be excluded?
Ankylosing spondylitis is associated with sacroiliitis, and the patient's X-ray showed a pelvis with a normal sacroiliac joint, making it less likely to be the cause. The symptoms, family history, and clinical presentation are more suggestive of conditions other than ankylosing spondylitis.
The patient has lateral thoracolumbar spine with intervertebral disc calcification (Fig. 2)
Fig. 2: Lateral thoracolumbar spine with intervertebral disc calcification
3 / 7
Which of the following is the least probable diagnosis?
While DISH can cause ligamentous ossification, the involvement of intervertebral discs is not a characteristic feature. The patient's lateral thoracolumbar spine with intervertebral disc calcification is more suggestive of other conditions.
She had also reported the occurrence of urine turning black after some time (Fig. 3). Physical examination demonstrated the blackish discoloration of ears as well as the pigmentation of sclera (Fig. 4).
Fig. 3: Change in urine color when exposed to air
Fig - 3
Fig. 4: Pigmentation of the ear and sclera
4 / 7
What is the most likely diagnosis for the patient's condition?
Alkaptonuria is a rare autosomal recessive disorder caused by a deficiency of the enzyme homogentisic acid oxidase. This deficiency leads to the accumulation of homogentisic acid, which causes dark pigmentation in connective tissues. The characteristic features of alkaptonuria include darkening of the urine upon standing or exposure to air (black urine), pigmentation of connective tissues (ochronosis), and musculoskeletal symptoms. In the presented case, the history of low back pain, difficulty in bending, restriction in back movements, scoliosis, early morning stiffness, pain on both knee joints, and the family history of similar complaints are consistent with alkaptonuria.
5 / 7
What is the primary enzyme deficiency in alkaptonuria?
Alkaptonuria is caused by a deficiency of the enzyme homogentisic acid oxidase, which leads to the abnormal catabolism of tyrosine. This deficiency results in the accumulation of homogentisic acid, causing the characteristic pigmentation and connective tissue deposition seen in alkaptonuria.
6 / 7
Which of the following clinical features is NOT associated with alkaptonuria?
Alkaptonuria is associated with black staining of undergarments, change in urine color upon standing (blue-black due to alkalinization), and premature osteoarthritis of knee and other major joints. However, blue pigmentation of the skin is not a characteristic feature of alkaptonuria.
7 / 7
Which radiological finding is characteristic of alkaptonuria?
Characteristic radiological findings in alkaptonuria include vertebral disc calcification, chondrocalcinosis, and osteoarthritis of multiple joints, especially the spine. These findings contribute to the clinical manifestations of premature degenerative arthritis in affected individuals.
The case study has been adopted from our journal Internet Journal of Rheumatology and Clinical Immunology. For further details regarding the case discussion, please visit: https://www.chanrejournals.com/jr/index.php/rheumatology/article/view/44/version/226/html
Your score is
We don’t spam! Read our [link]privacy policy[/link] for more info.
Check your inbox or spam folder to confirm your subscription.
You must be logged in to post a comment.