Dark Knuckles: Causes & Tips To Lighten Them

Dark knuckles whether it is hand or leg fingers seen, are common in black people and are especially seen in Asia and India.

However, it can be seen in people, who facing health issues, signs of early illness, or other issues that cause dark knuckles.

Exposure to ultraviolet radiation from the sun is known to trigger pigmentation disorders.

Vitamin B12 deficiency is the most common reason for it, especially for those who are vegetarians because most B12 is found in animal food.

Causes of Dark Knuckles

There are several causes of dark knuckles (pigmentation), which could be signs of health conditions, and signs of medication intake.

Here are the top causes of dark knuckles which include:

Vitamin B-12 deficiency

B-12 helps prevent anemia and contributes to the production of DNA and RNA, maintaining a healthy nervous system, as well as regulating blood glucose levels.

Because this vitamin has far-reaching effects on your body, it can be extremely dangerous to have too little B-12 in your system (2)

Dark knuckles commonly occur in vitamin B12 deficiency, which could be having a megaloblastic anemia component (3)

Vitamin B-12 deficiency is an under-recognized, easily found-cause of anemia, fatigue, and neurological symptoms.

Dark knuckles have been observed in 19% of patients with megaloblastic anemia and sometimes only indicate vitamin B12 deficiency (4)

Symptoms of a deficiency (5) include:

Allergic Reaction

If you don’t have a deficiency, then you have to think about other conditions like what kind of contact things that you are coming to.

It can be simple chemicals like detergents, liquids soaps, and creams, allergic to certain things that point to dark knuckles skin.

Our Immune system is responsible for defending the body against bad bacteria and viruses or substances like pollen, dust, etc

These substances are known as allergens, and when your body reacts to them, it causes an allergic reaction.

But in some cases, our immune system will defend against substances that typically don’t threaten the human body.

Habitual Rubbing/Friction

If you habit of hand rubbing like biting nails, cracking knuckles, etc, then most probably you have seen dark knuckles.

And if you work that causes friction in your knuckles, which over time removes upper skin, and leads to darker and thin skin.

Cracking knuckles is not harmful, is similar to the popping sound that comes from the knees, when you get up, and squat.

Insulin Resistance

Dark knuckles can be seen in diabetes or pre-diabetes people, where insulin levels are increased in the blood.

In some people, insulin resistance occurs due to genetics, where the pancreas makes less insulin.

There are some people who are more prone to insulin resistance syndrome including:

Acanthosis nigricans is similar to the dark knuckle (where certain areas of skin including neck, armpits, etc become thick, dark, with folds and creases.

Psoriasis & Eczema

Psoriasis is a skin disease that causes a rash, and dry, scaly patches, which are most commonly seen in knees, elbows, on hands.

When psoriasis is cured, then it leaves behind dark spots (6)

Eczema is also a skin condition, where the skin becomes very dry, itchy, and swelled skin, commonly skin in young children.

However, it also leaves dark spots in that area after being cured, but it is not contagious.

Genes or Family History

If you don’t have a vitamin B12 deficiency, and no other skin disease, then genetics may play a role in dark knuckles.

If your parents are allergic to certain things and have dark knuckles, then it may occur to you also.


Acanthosis Anglicans and obesity were first noticed in 1947 in a 17 years old boy.

A 2020 report, showed that about more than 2 billion adults (39% of the adult global population) were overweight.

Obesity is the most common reason for acanthosis Anglicans or dark knuckles (7) (8)

Gender also plays a role in obesity, women (BMI ≥35 kg/m2) have been found to be more prone to obesity than men (9).

Being overweight has several effects on the body which include:

  • effect mental health include – low self-esteem, mood disorder, quality of life effects, communication problems
  • diabetes
  • more chance of heart attack
  • difficulty in being pregnant
  • low testosterone level
  • decrease quality of life
  • low bone density
  • more prone to getting disease or illness

Treatment of Dark Knuckles

So if you see or feel that the knuckles have become dark, make sure that you speak to your dermatologist.

They can do very simple blood tests to diagnose what exact reason for dark knuckles and you may be able to treat the dark circles very well.

To manage or treat dark knuckles first find causes. for example:

  • If you have obese then you should reduce your weight.
  • If you have diabetes or insulin resistance then may take prescription medicine.
  • vitamin B12 deficiency can improve after supplements.
  • If psoriasis & Eczema are the reason for your dark knuckles then creams and moisturizers are helpful.
  • A friction person can also use motion, lotion, and creams.

Tips To Lighten Them

There are several tips, ways, or treatments to lighten dark knuckles which include:

Laser Treatment

The doctor may consult you about laser treatment to peel off pigmentation, which can be used that are very effectively for skin brightening.

You should always consult with a professional physician and the most appropriate treatment before starting any new regimen.


It is one of the best treatments for dark knuckles, but which cream is the best? there are several lotions or creams.

But make sure the cream should have these ingredients which you use twice a week are:

  • Glycolic acid
  • Urea
  • lactic acid (urea and lactic acid gently exfoliate and moisture)

These creams are – Xeroclear cream and Xerina cream, also used Glycolic acid-based creams are G-peel and Glyco 120, and Glyaha cream.

NOTE: It takes time to see results, so should use it continuously before bedtime for 2 to 3 months.


There are some home remedies that you can try at home easily which include:

  • Baking soda mixed with water, and make a paste, then applied on your knuckles for 15 to 20 minutes.
  • lemon juice you just rub it onto the black area or in your knuckles for about 10 to 15 minutes. Do it for 2 weeks continuously.


There are some vital oil that is effective in treating dark knuckles (7)

In a 2011 study, results showed that bio-oil for 12 weeks can significantly improve uneven skin tone, 71% of participants showed.

Studies show that Bio-oil is an effective treatment for dark spots on the face caused by genetics or UV rays exposure.

Down Line

Dark knuckles are most commonly seen in vitamin B12 deficiency people, and vegetarians are more prone to B-12 deficiency.

It may also indicate health issues, so if you see pigmentation on another body area like the neck, armpits, etc then consult the doctor.

First, consult your dermatologist before using any cream, lotion, or medication, it may show adverse effects.


Hello, I'm Sahil bisht, I am a Mechanical engineer, As well as, aspiring blogger with an obsession for health. This blog delicate to people who want to learn in health.

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