Ochronosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Ochronosis?
A rheumatologist (a joint doctor) and a geneticist (a doctor who treats inherited conditions) often care for people with ochronosis. A dermatologist (a skin doctor) can help if a skin product is the cause. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is ochronosis?
Ochronosis is a buildup of dark blue-black pigment in connective tissues. Connective tissues include the joints, tendons, and ligaments. Cartilage is one of them. Ochronosis is a characteristic feature of alkaptonuria, a rare inherited condition. Ochronosis can also be an acquired condition that has nothing to do with alkaptonuria. Both types are covered below.
Symptoms
Most symptoms of alkaptonuria come from the pigment buildup and appear slowly. The first signs usually show up around age 30. They can include:
- Urine that turns black or very dark when it is exposed to air. This is often the first symptom, but the color change may not happen right away.
- Blue-black color in the whites of the eyes, the outer ears, and the hands.
- Arthritis, a joint problem that usually affects the spine and large joints such as the hips and knees.
- Back pain, because the discs between the spine bones can harden.
- Kidney stones, and prostate stones in men. Passing the black stones can be extremely painful.
Tendons and ligaments can become weak and may tear more easily. The heart valves can also narrow in some people.
Causes and who gets it
Alkaptonuria is caused by changes in the HGD gene. This gene makes an enzyme, a protein that helps the body break down certain amino acids. When the enzyme does not work well, a substance called homogentisic acid builds up. It settles in connective tissue and darkens cartilage and skin.
The condition is inherited in an autosomal recessive pattern. Both copies of the gene must have a change to cause it. The parents each carry one changed copy and typically do not have symptoms.
Acquired ochronosis is different. It can follow contact with substances such as benzene and phenol. It has also followed long-term use of some medicines. These include the skin-lightening agent hydroquinone and the antibiotic minocycline. This form can be reversible.
How doctors diagnose it
Doctors use your symptoms, a detailed history, an exam, and special tests. Doctors suspect alkaptonuria in people with dark urine. Very high levels of homogentisic acid in the urine point to the diagnosis. Imaging tests can show how much the joints, spine, or heart valves are affected.
Genetic testing is available, but it is not required to confirm the diagnosis. In people over 40, doctors may suggest an echocardiogram, an ultrasound of the heart. The joint symptoms can look like rheumatoid arthritis, ankylosing spondylitis, or osteoarthritis.
Treatment
In June 2025, the US Food and Drug Administration approved nitisinone (Harliku), the first medicine to treat alkaptonuria in adults. It lowers the homogentisic acid in the urine. Your doctor will check blood tests and your eyes while you take it. The rest of care is aimed at the symptoms each person has. Care is tailored to the person and needs long-term follow-up.
- Anti-inflammatory medicines are often used for joint pain. In severe cases, stronger pain medicines may be advised.
- Physical and occupational therapy can help keep muscles and joints strong and flexible.
- About half of people with alkaptonuria need a hip, knee, or shoulder joint replacement, often by age 50 to 60.
- Surgery to replace heart valves, or for painful kidney or prostate stones, is sometimes needed. Spine surgery is needed only infrequently.
- Activities that strain the spine and joints, such as high impact sports or heavy manual labor, should be avoided.
- Genetic counseling may help people with alkaptonuria and their families.
On their own, diet changes have generally not worked well. A strict low-protein diet is hard to keep up and can cause problems of its own. Tell your doctor about any skin-lightening product or medicine you use for a long time, and follow your doctor's instructions about it.
When to see a doctor
See a doctor if your urine turns dark or black in the air, or if you notice blue-black color in your ears or the whites of your eyes. Also get checked for back or joint pain that does not go away. Passing the black stones can be extremely painful, so get medical care right away if you have severe stone pain.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. A direct primary care doctor can review your symptoms, order first tests, and follow your joint health over time. They can also help coordinate care with a geneticist, a rheumatologist, and a surgeon.
Common questions
Is ochronosis the same as alkaptonuria?
No, they are not the same. Alkaptonuria is an inherited condition, and ochronosis is a characteristic feature of it. Ochronosis can also happen without alkaptonuria, as an acquired condition.
Does ochronosis from alkaptonuria shorten life?
No, people with alkaptonuria generally have a normal life expectancy with appropriate medical management. Chronic pain and trouble moving can still develop.
Can skin-lightening products cause ochronosis?
Yes, it can happen. Some people developed ochronosis after long-term use of the skin-lightening agent hydroquinone.
Does dark urine mean I have alkaptonuria?
Not by itself. Doctors suspect alkaptonuria in people with dark urine, and then they check the urine for homogentisic acid.
Sources
- MedlinePlus Genetics - Alkaptonuria
- National Organization for Rare Disorders (NORD) - Alkaptonuria
- PubMed Central - Harliku (nitisinone) for alkaptonuria
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
