This article reveals the differences between subungual hematoma and melanoma:
Subungual Hematoma (Bleeding Under Nail)
It refers to blood that is trapped under the nail after trauma. The damage is caused by a crush injury or a direct blow (such as – getting a finger pinched in a doorway) to the distal phalanx.
The injury is classified by the percentage of the area beneath the nail which is involved and is manifested by dark red-to-black discoloration and pain of the nail bed.
Melanoma is a type of cancer which develops in the pigment cells present in the skin, called melanocytes. It is one of the fastest-growing cancers, particularly in young women under 30.
Subungual melanoma is a form of skin cancer which occurs under the fingernails. An estimated 40 percent of subungual melanomas occur in the toenails, whereas the rest 60 percent occur in the fingernails.
Subungual Hematoma (SUH)
SUH occurs when an injury (like – hitting your finger with a hammer) breaks open blood vessels under the nail, causing blood to become trapped in one spot. In addition, it can be caused by repetitive trauma in athletes, like dancers or marathon and ultramarathon runners as well as due to ill-fitting footwear.
Subungual Melanoma (SUM)
The exact cause of development of SUM is unknown. But, it is known that its development is not related to sun exposure. Potential causes may include:
- a familial history of melanoma or other related cancerous tumors;
- taking medicines which suppress the immune system;
- a condition which suppresses the immune system, like HIV or AIDS;
- fungal or bacterial infections of the nail bed;
- previously damaged skin through radiotherapy treatment;
- trauma to the nail bed itself;
- age – SUM is more common in people over 65 years.
Common symptoms of SUH can include:
- tenderness as blood accumulates under tension in the nail bed;
- the nail is discolored;
- it feels like there is pressure under the nail;
- the nail feels sore.
Common symptoms of SUM can include:
- cracking, thinning, or distortion of the nail plate;
- black or brown streaks in the nail without any known injury;
- a nail which bleeds or develops a nodule;
- deformed and damaged nail;
- darkening skin next to the nail;
- toenails or fingernails which separate from the nail bed;
- a bruise on the nail which will not heal or moves up as the fingernail grows;
- streaks on the nails which increase in size.
A doctor can often diagnose a SUH based on any recent trauma you report and visual inspection of the nail. Also, the following tests may be done:
- a biopsy – it is a procedure to remove a part of the nail to send for tests to a lab;
- an x-ray of the foot or hand – it may be done to check for broken bones;
- a dermoscopy – it is a medical procedure that is used to look for damage to the nail with the help of a microscope.
Like most cancers, early detection of SUM is optimal. Most doctors diagnose this type of melanoma by examining the spot causing concern and by doing a punch biopsy.
The treatment of a SUH requires subungual decompression, that is typically done by creating small holes in the nail plate.
In the case of a subungual hematoma that is greater than 50 percent of the nail bed, the nail should be removed. Also, the nail bed laceration should be repaired for optimal functional and cosmetic results.
Trephination (a surgical intervention where a hole is incised) is not indicated if:
- the injury was over 24 hours ago since the blood clotted and will not flow out;
- there is no significant pain;
- the hematoma encompasses only 25 percent of the nail bed.
If trephining is used, the sufferer should understand the potential risk of developing osteomyelitis (infection of the bone).
Treatment of SUM may include:
- targeted therapies;
- immunotherapy – it aims to stimulate the immune system to fight cancerous cells;
- radiation therapy – it is used as a palliative treatment to decrease pain;
- chemotherapy – it is given either systemically directly into the tumor or through a vein.
- trim your toenails before running;
- use suitable running shoes of the correct size;
- in case of downhill running, your shoes should be laced tighter at the front part of the shoe;
- try to prevent potential injuries to your nail, especially when you are in your home;
- instead of cotton socks, use wicking socks or Drymax sports socks;
- don’t use nail polish on the toenail;
- feet should be kept dry during running.
- wear lightweight, loose-fitting clothing like long pants or long-sleeve shirts;
- avoid tanning salons;
- avoid nail bed injuries;
- boost your immune system with a regular diet rich in fruits, veggies, legumes, seeds, nuts;
- avoid junk foods;
- do not smoke tobacco as well as avoid second-hand smoking;
- do not drink alcoholic beverages;
- practice regular physical exercise;
- sleep 7 to 8 hours per night;
- regularly spend time in nature;
- reduce your stress with the help of mindfulness meditation, Tai Chi, or yoga.
Bottom Line – Subungual Hematoma vs Melanoma
Subungual hematoma, also known as runner’s toe or tennis toe, is an injury of the nail bed in which bleeding develops under the nail. Bleeding from the rich vascular nail bed leads to substantial pain and discomfort. The injured area under the nail may also have a blue-black color. Trephining is a good method of relieving pain and releasing trapped blood.
Melanoma is a form of skin cancer which occurs when melanocytes (pigment-producing cells) mutate and become cancerous. Subungual melanoma, also referred to as cancer of the nail unit, is a type of melanoma of the nail that affects the nail matrix (the tissue beneath the nail base).
SUM commonly resembles normal bruising of the nails and may be difficult to identify from a subungual hematoma. SUM can cause a dark mark to form under the nail, but, it is not linked to an injury and it does not cause pain.
Therefore, to determine whether your nail discoloration is caused by a SUH or SUM, your doctor will mainly focus on whether you engage in a sport, such as tennis or running, or you have had a recent injury to your nail.
Subungual melanoma appears like a streak along the nail. As this type of melanoma progresses, there may be a few streaks of varying shades on the affected nail. Almost fifty percent of these streaks are non-pigmented, whereas the other fifty percent are blue, brown, or black.
Sources https://www.ncbi.nlm.nih.gov/pubmed/22351556 https://www.aafp.org/afp/2012/0415/p779.html https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5762474/ https://www.jprasurg.com/article/0007-1226(92)90051-X/pdf