Black neck also called “dark neck” refers to the darkening of the neck area as compared to surrounding areas. It can occur due to several reasons. In most cases, it is not concerning. However, in some cases, it can be a sign of some serious medical condition.
Table of Contents
Symptoms
Black neck appears as dark or discolored areas on the back and sides of the neck. One may also see symptoms like thickened skin, skin tags, or a velvety appearance.
In addition to the neck, other areas of the body like the axilla or groin may be affected.
Note: One should see a doctor if the black neck appears suddenly as it can be a sign of a serious underlying condition.
Causes and treatment
Black neck or dark neck may occur due to several reasons or underlying conditions. Below you will find 7 possible causes and treatments for each.
1. Acanthosis nigricans
The black neck can often be due to acanthosis nigricans. Acanthosis nigricans is a skin condition characterized by the darkening of the skin. The skin may become thick and velvety or leathery.
The affected skin may itch, develop skin tags, and can have an odor. It can affect folds of the skin like in the axilla, neck, groin, and under the breasts. It is more common in darker skin tones.
Acanthosis nigricans is usually seen in obese, diabetics, or in people with a tendency to develop diabetes. There can be several other reasons behind its occurrence:
- Due to medications like oral contraceptives, oral steroids, hormones, and subcutaneous insulin.
- Hormonal problems associated with disorders of the adrenal gland, pituitary, or polycystic ovarian disease (PCOD).
- It can also be associated with some autoimmune diseases like systemic lupus erythematosus, Sjogren syndrome, scleroderma, and Hashimoto’s thyroiditis.
- Rarely, it can be associated with cancer, most commonly stomach cancer.
- It can be congenital due to an abnormal gene and can present in childhood.
It can occur in healthy people without any medical conditions as well.
It usually develops slowly over time. The sudden appearance of these patches may be more concerning and require medical attention.
Acanthosis nigricans can be diagnosed clinically by a doctor. Your doctor may do additional testing to determine the underlying cause. Additional testing may include blood testing for diabetes or hormones. Sometimes, a skin biopsy may be required.
It is also important to tell your doctor about any over-the-counter medications or supplements you are taking.
Treatment
In most cases, treating the underlying cause like diabetes, hormonal imbalance, etc. may help in improving this skin condition. In addition, some topicals may be helpful. These include:
- Exfoliants that get rid of layers of dead skin cells. These include salicylic acid, glycolic acid, and lactic acid.
- Topical retinoids (Vitamin A derivatives) like retinol or prescription tretinoin can increase the turnover of the skin cells resulting in the removal of the excess pigment.
- Calcipotriol (Vitamin D derivative).
In more resistant cases, dermabrasion or laser therapy may be useful.
Additional measures to improve acanthosis nigricans:
- Maintain a healthy lifestyle.
- Lose weight.
- Eat a healthy diet with fruits and vegetables.
- Limit intake of processed food.
- Protect skin from the sun.
2. Post-inflammatory hyperpigmentation (PIH)
Any inflammation, injury, or trauma in the neck area can leave behind areas of hyperpigmentation.
This can be from tight clothing, jewelry, harsh aggressive scrubbing, or any inflammatory skin condition like eczema.
In addition, contact with any irritant can lead to contact dermatitis which can leave behind areas of hyperpigmentation. Skin care products may contain ingredients that can act as an irritant for people with sensitive skin.
All this can lead to post-inflammatory hyperpigmentation or PIH.
Treatment
The treatment options for post-inflammatory hyperpigmentation include:
- Over-the-counter retinoids like retinol.
- Alpha-hydroxy-acids like glycolic acid and lactic acid
- Niacinamide.
For resistant cases:
- Prescription retinoids like tretinoin and hydroquinone may be helpful.
- Chemical peels with acids like glycolic acid, lactic acid, and trichloroacetic acid can help get rid of dead skin cells on top.
- Microdermabrasion involves the use of small rough particles to get rid of surface dead skin cells. It can improve areas of hyperpigmentation. You may need several sessions before you see improvement.
- Lasers can target and destroy the melanin pigment which is eventually removed by our body. One may need 3-6 sessions to see improvement.
Additional measures to follow:
- Make sure the clothing around your neck is comfortable.
- Patch test new products if you have sensitive skin.
- Do not scrub, instead use chemical exfoliants a few times a week.
3. Tinea versicolor
Black neck can also occur due to fungal infections like tinea versicolor. Tinea versicolor is a common skin condition that occurs due to a fungus – Malassezia. This fungus is normally present on the skin. However, in this case, there is an overgrowth of Malassezia.
This can happen due to:
- Hot and humid weather
- Weak immune system
- Oily skin
- Hormones
It results in areas of discoloration which can be lighter or darker as compared to surrounding areas. There can be scaling and itching. It usually appears on the back, chest, neck, and arms.
Tinea versicolor can be diagnosed clinically by looking at it. In some cases, skin scrapings may be taken and seen under a microscope to confirm the diagnosis.
It can recur in hot and humid weather.
Treatment
Tinea versicolor usually responds to over-the-counter antifungals in the form of cream or gel with terbinafine or clotrimazole.
Anti-dandruff shampoos with ingredients like selenium sulfide, ketoconazole, and zinc pyrithione may be useful as well. One will need to lather the shampoo and leave the lather on the skin for a few minutes before rinsing.
In severe cases, prescription-strength oral or topical antifungals may be needed. It may take some time for discolored areas to disappear or even out completely.
4. Dermatitis neglecta
Black neck can appear if it’s not cleaned or washed well. This is called dermatitis neglecta.
Dermatitis neglecta also known as “unwashed dermatosis” is a skin condition that occurs due to lack of hygiene. A person often does not wash the affected area which results in a build-up of dirt, bacteria, sweat, and sebum on the skin.
It can appear as hyperpigmented patches. In severe cases, the skin can become thickened. It is often seen in the elderly, disabled, sick, or people with sensitive skin.
Treatment
- Cleaning the area with soap and water regularly can clear the area.
- An alcohol wipe can also clean the area.
- For severe cases, keratolytic (which can slough away layers of dead skin cells) can be used. These include urea, glycolic acid, and salicylic acid.
- Patients should be educated about the importance of hygiene and regular cleaning to prevent its recurrence. Cleansing skin can not only get rid of oils and dirt but also dead skin cells.
5. Pigmentation due to drugs
Discoloration of the neck can be caused by some drugs. Drug-induced pigmentation can be due to several reasons:
- Accumulation of melanin in response to sun or skin injury.
- Accumulation of the drug itself.
- Deposition of other pigments.
Some drugs which can lead to pigmentation are:
- Nonsteroidal anti-inflammatory drugs
- Antimalarials
- Amiodarone
- Cytotoxic drugs
- Tetracyclines
- Psychotropic drugs
Treatment
In most cases, the pigmentation will resolve once the drug is discontinued. However, in some cases, pigmentation may not go away. So, other treatments like lasers may be necessary to get rid of pigmentation.
6. Reaction to hair products
Black neck can be a tell-tale sign of chronic irritation from hair products like hair dyes or hair styling products.
Treatment
If you suspect this, patch test your hair products before using them, and choose hair products free of fragrance or meant for people with sensitive skin.
If the area is red and irritated, let it heal. For residual hyperpigmentation, retinol, lactic acid or urea-containing skin care products can be beneficial.
For more resistant cases, prescription medications or in-office procedures like chemical peels and lasers may be helpful.
7. Sun exposure
Prolonged exposure to the sun can result in the darkening of the skin, referred to as a tan. This occurs due to an increase in the melanin pigment.
Treatment
Niacinamide, retinoids, and alpha-hydroxy acids like lactic acid can be helpful in decreasing the dark areas on the neck.
The best way to avoid it is by limiting sun exposure (especially during peak hours 11 am to 3 pm) and by using a broad-spectrum sunscreen or a sunscreen that can protect from both UVA and UVB rays.
Diagnosis
Black neck can be a symptom of an underlying condition. So, it’s important to see a doctor for proper diagnosis and treatment.
Your doctor will do a physical examination of the affected area. In some cases, they may do additional testing. This may include blood tests to check for diabetes or other hormones, imaging, or other tests.
Prevention
1. Weight management
If you are obese or diabetic, losing weight can reduce your chances of getting a dark neck or improve the hyperpigmented areas if you already have them.
2. Gentle skincare
- Be gentle with your neck skin.
- Always use a mild cleanser and moisturizer for everyday care.
- Do not use physical scrubs, instead use chemical exfoliants sparingly.
- Do not rub or tug on the skin, instead pat it.
- Always clean both the front and back of the neck to get rid of all dead skin cells, oil, and dirt.
3. Sunscreen
Sunscreen is necessary not only for the face but also for the neck. Make sure to cover both the front, sides, and back of the neck with sunscreen.
In addition to sunscreen, use wide-brimmed hats or scarves to protect the back of the neck from the sun.
4. Comfortable clothing
Avoid wearing tight clothes around your neck. Constant friction can lead to skin darkening.
Key points
Dark neck, or black neck, is a skin condition with dark areas or areas of hyperpigmentation (discoloration) on the neck. It can happen for many reasons. It is very commonly seen in obese and diabetics.
It’s important to see a doctor to know the root cause as in some cases this is a sign of a serious underlying health condition.
Topicals like retinoids and keratolytic may help. In resistant cases, chemical peels, microdermabrasion, and lasers may be useful.
References
- Phiske MM. An approach to acanthosis nigricans. Indian Dermatol Online J. 2014 Jul;5(3):239-49. doi: 10.4103/2229-5178.137765. PMID: 25165638; PMCID: PMC4144206.
- Brady MF, Rawla P. Acanthosis Nigricans. [Updated 2022 Apr 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
Disclaimer: This blog post is for information purposes only and does not replace medical advice.