The causes range from harmless to serious ones that need to be shown to the doctor. In some cases, it is caused by an underlying condition.
The skin on our neck can get darkened easily due to multiple reasons like hormonal imbalance, sun exposure, or other skin-related conditions. Apart from discoloration, there can also be a change in the texture of the skin, such as thickening or softening of the surrounding skin. It can be accompanied by darkening in other areas as well, such as the armpit. While it may be harmless in most cases, it is always a good idea to get any type of abnormality checked out by a doctor.
For many, it is caused due to hyperpigmentation that happens in people over the age of 40. However, it can happen to kids and younger adults as well. The reasons for dark patches on the neck for them would be different, however.
If you want to know more about what could be causing it, read on:
This is also known as solar lentigines or sun damage. They are usually brown, black or gray and can vary in size. They usually appear on the body surfaces most exposed to the sun, like face, hands, neck, upper back. They are referred to as age spots or liver spots. The number of spots can increase as we age and with repeated sun exposure. These look like tiny spots and can increase in large numbers. They look like freckles, but freckles tend to be smaller in size and can occur earlier in life. Solar lentigines can show up in younger people too if they spend a lot of time in the sun without skin protection, as per MayoClinic.
This is a condition in which the skin in the folds and creases of the body look dark and velvety. The affected areas can also become thickened. Mostly, this affects armpits, groin, and neck. This is more common for people who are obese or have diabetes. It can also occur in children and those who do have it can have the risk of developing type 2 diabetes. In some rare cases, it can be a sign of a cancerous tumor in an internal organ, such as the stomach or liver. There is no specific treatment available for this condition and treating the underlying conditions can restore it to a normal color and texture to some extent, as per MayoClinic.
This condition can cause skin color changes when it hasn't been washed well over a period of time. This can happen when sweat, bacteria, sebum, and other matter builds up due to inadequate hygiene practices. This is also called "unwashed dermatosis." This is a rare disorder but it can be fixed by scrubbing the area with soap, water, or alcohol. It can be prevented by maintaining proper personal hygiene, according to Healthline.
There are some drugs that can cause hyperpigmentation. This hyperpigmentation can show up in multiple places on the body, including the neck. The color could range from dark brown to blue-black and can be treated by stopping the particular drug. In some cases, the discoloration can be long-term or permanent. For those cases, laser treatments might be the way to go.
Some of the drugs that can cause skin discoloration include nonsteroidal anti-inflammatory drugs, phenytoin, antimalarials, amiodarone, antipsychotic drugs, and tetracyclines, as per Healthline.
Discoloration on the neck can be caused by a sun allergy as well. It usually shows up as an itchy red rash and is usually in the "V" of the neck, the back of the hands, the outside surface of the arms and the lower legs. In some rare cases, it can be severe, producing hives or small blisters that could spread to parts of the body that are clothed. It occurs when the sun causes changes in sun-exposed skin. It's not clear why this happens, as per Harvard health.
These are a type of vascular birthmark and can appear anywhere on the body as mild red marks. This is the most common type of vascular birthmark. There are two ways in which these show up. First are the angel kisses, which appear on the forehead and eyelids. They vanish after the age of two. Then, there are the stork bites, which will appear on the back of the neck and can last into the adult years. These birthmarks are often mild and always harmless, so they don't need to be treated, as per Cleveland Clinic.
References:
https://www.mayoclinic.org/healthy-lifestyle/adult-health/multimedia/sun-damage/sls-20076973?s=4
https://www.mayoclinic.org/diseases-conditions/acanthosis-nigricans/symptoms-causes/syc-20368983
https://www.healthline.com/health/black-neck#causes
https://www.health.harvard.edu/a_to_z/sun-allergy-photosensitivity-a-to-z
https://my.clevelandclinic.org/health/articles/11014-pigmentation-abnormal-pigmentation
Disclaimer : This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.