What is Ochronosis and what are the causes?

Ochronosis is a rare condition characterized by the blue-black discoloration of connective tissue, including the skin, due to the accumulation of homogentisic acid. This pigmentation occurs in the collagen of the skin, leading to dark discolorations often observed in the ear, the eyes, and skin areas regularly exposed to sunlight. It is predominantly found in individuals with alkaptonuria, a genetic disorder in which the body is unable to properly break down certain proteins.

In addition to the natural form of ochronosis, it can also be a side effect of prolonged use of certain skin lightening creams that contain hydroquinone. This leads to a paradoxical darkening of the treated skin areas. In this context, ochronosis is often seen as an unwelcome complication of cosmetic treatments, especially in non-western countries where higher concentrations of hydroquinone are used.

Two Types of Ochronosis

Endogenous Ochronosis

Endogenous ochronosis is a condition that is genetically determined and occurs in people with a rare metabolic disease called alkaptonuria. Alkaptonuria means that the body has trouble breaking down a specific amino acid, known as homogentisic acid. Normally, our body should break down this amino acid efficiently and excrete it, but in alkaptonuria the acid remains in the body.

This excessive homogentisic acid tends to accumulate and deposit in various body tissues, including the skin, cartilage, and even in the heart and blood vessels. Over time, this accumulation causes a dark, blue-black discoloration of the affected areas, especially in places where the tissue is regularly under pressure or damaged. You can imagine it as a kind of ink that slowly spreads through the tissue, causing it to permanently discolor. This process illustrates how a metabolic error deeply affects a person’s physical appearance, with all the psychosocial and medical implications thereof.

Exogenous Ochronosis

Exogenous ochronosis is a skin condition that arises from prolonged exposure to certain chemical substances. A common cause of this condition is the use of hydroquinone, an ingredient often present in creams intended to lighten the skin.

When you use hydroquinone, especially for a prolonged period, it can lead to unwanted accumulation of pigment in the skin. This mechanism works as follows: hydroquinone suppresses an enzyme that is essential for the production of melanin, the natural pigment that gives our skin, hair, and eyes their color. Normally this ingredient helps reduce dark spots by decreasing melanin production. However, with long-term use, the opposite effect can occur where the breakdown of melanin is no longer well managed, resulting in the accumulation of dark, blue-black pigments in the skin.

You can imagine it as a paint that slowly accumulates on a wall where you keep painting more layers without removing the old ones. Instead of making the wall lighter, it becomes darker and uneven in some places. This accumulation results in the characteristic blue-black discoloration that becomes visible on the skin, which medically is not only a cosmetic issue, but can also indicate deeper damage in the structure of the skin.

How to recognize ochronosis

Ochronosis is a condition that can be recognized by some notable characteristics on the skin and in the body. Below I explain how you can recognize both the endogenous and exogenous forms:

1. Dark, blue-black spots on the skin: These discolorations are typical for ochronosis. In endogenous ochronosis, caused by a genetic disorder called alkaptonuria, these spots often appear on the cartilage and skin that is frequently exposed to sunlight. In exogenous ochronosis, often caused by the prolonged use of skin lightening agents such as hydroquinone, you find these discolorations primarily in places where the creams have been applied.
2. Discoloration of cartilage: This is a notable characteristic of endogenous ochronosis. The cartilage, such as in the ears and nose, can take on a dark blue or black hue. This occurs because homogentisic acid, which accumulates in people with alkaptonuria, deposits itself in the cartilage.
3. Joint problems: With endogenous ochronosis, in addition to skin and cartilage discolorations, joint problems can also occur. This is due to the accumulation of pigment in the joints, which can cause pain and stiffness.
4. Discoloration of other tissues: In severe cases of endogenous ochronosis, the discoloration can extend to other tissues in the body, indicating a widespread accumulation of homogentisic acid.

Prevention and Treatment

Prevention and treatment of ochronosis vary depending on whether it is the endogenous or exogenous form. Here I explain how you can tackle both:

For endogenous ochronosis: This form is genetic and related to a disease called alkaptonuria. Unfortunately, there is no definitive cure for this condition. However, the symptoms can be managed. One approach is through dietary changes; certain foods rich in protein may be best avoided as they can increase the amount of homogentisic acid in the body. In addition, there are medications available that help reduce the buildup of this acid in the body, thereby limiting the symptoms of ochronosis.

For exogenous ochronosis: This form is caused by prolonged use of certain chemical substances in skincare products, especially hydroquinone, which is often found in skin bleaching creams. The best preventive measure is to avoid products that contain this chemical substance. There are alternative skincare products without hydroquinone that are safer for long-term use. If you notice symptoms of exogenous ochronosis, such as skin discoloration, it is important to consult a dermatologist. A professional can provide suitable treatment options, such as creams that can help reduce discoloration or procedures that can remove the affected skin layers.

Alternative Bleaching Cosmetic Ingredients

For everyone who is looking for safer alternatives to hydroquinone in skin brightening products, there are several other ingredients that can help reduce hyperpigmentation without the risk of exogenous ochronosis. These ingredients work at different levels of the pigmentation process, such as the inhibition of the enzyme tyrosinase, which is essential for the production of melanin, or by influencing the transfer of pigment (melanosomes) to the skin cells. Here are some effective alternatives:

• Niacinamide (Vitamin B3) and Vitamin C are potent antioxidants that can inhibit tyrosinase activity, leading to less production of melanin.
• Arbutine, a derivative of hydroquinone, and kojic acid also work by inhibiting the activity of tyrosinase, but are milder than hydroquinone.
• Azelainezuur has a dual function: it inhibits tyrosinase and reduces inflammation, making it particularly good for people with acne and rosacea.
• Liquorice root and Aloe Vera contain components that help to reduce tyrosinase activity and also provide anti-inflammatory benefits.
• Resveratrol, found in grapes and berries, and Emblica (Indian gooseberry), offer antioxidative benefits that can regulate melanin production.
• Peptides in skincare products can help modulate the signaling pathways that stimulate melanin production.

These ingredients are not only effective in reducing pigmentation but are also less aggressive, making them more suitable for long-term use without serious side effects such as ochronosis. It is always a good idea to first test these products on a small patch of skin to avoid any allergic reactions and to see how your skin reacts to it.

Now that you’re here

Hydroquinone is a powerful ingredient often used in dermatological treatments to reduce pigmentation spots, such as in melasma and post-inflammatory hyperpigmentation. This chemical compound suppresses melanin production in the skin. Due to its popularity and recent attention to its safety, it is important to know the functioning, composition, and possible risks of hydroquinone. Read more about hydroquinone