Difference between Blood Blister and Melanoma

Blood blisters and melanoma are two different skin conditions that can appear similar in their early stages. Blood blisters are caused by trauma to the skin, while melanoma is a type of skin cancer that develops in the melanocytes, the cells that produce the pigment melanin. Despite their similarities in appearance, there are significant differences between these two skin conditions.

What are Blood Blisters?

A blood blister occurs when the subdermal tissues are destructed without piercing the skin. So, when the skin is pinched, bruised and rubbed, a blood blister will form. A blood blister appears like a blood-filled ball covered by skin.

The presence of blood in a blister shows the presence of high pressure component. Unlike friction blisters which contain a clear fluid, blood blisters comprise of a red liquid. The fluid begins as a light red color that appears darker after some time. Most of the blood blisters cause minor discomfort and irritation. However, some blisters are extremely painful in case there is infection.

It is usually self-diagnosable and heals on its own in 1-2 weeks, but needs medical attention in case there is severe infection. Applying antibiotic cream over the blister helps to heel it faster.

What is Melanoma?

Melanoma is the most dangerous form of skin cancer. The malign tumours grow when the unrepaired Deoxyribonucleic acid damage to the cells of the skin causes mutations. These mutations cause the damaged skin cells to multiply rapidly and develop malignant tumours. This damage to the skin is mostly caused due to UV rays form sunshine or tanning beds.

Melanoma grows when the pigment-producing cells which are responsible to give colour to the skin becomes malign or cancerous.

The probability of developing a melanoma increases with age. It is the most commonly registered cancer in men aged between twenty-five – forty-four and the 2nd most commonly registered cancer in women between the same age group.

When the doctors assess a suspicious mole, blister or freckle, they mostly use the below given assessment criteria:

ABCDE of melanoma:

  • A for Asymmetrical shape – Melanoma moles are not regular and symmetrical

  • B for Border – the border of the Melanoma lesions or freckle is irregular

  • C for Colour – uneven distribution of colour (blue, black, brown, tan etc)

  • D for Diameter – Melanoma mole is greater than six mm in diameter

  • E for Evolution – Melanoma lesion is enlarging or changing

Glasgow 7-point checklist (7PCL):

  • Change in size of the mole

  • Shape is not regular

  • Irregular pigmentation

  • Diameter > 7mm

  • Inflammation

  • Itch or altered sensation

  • Border is not regular

Differences: Blood Blister and Melanoma

One of the key differences between blood blisters and melanoma is their causes. Blood blisters are usually caused by trauma or injury, while melanoma is caused by genetic mutations in the DNA of melanocytes. Blood blisters can occur anywhere on the body, but melanoma typically develops on areas of the skin that are frequently exposed to the sun, such as the face, arms, and legs.

Another key difference between blood blisters and melanoma is their treatment options. Blood blisters usually heal on their own within a few days to a few weeks, but if they are particularly large or painful, a doctor may choose to drain them to relieve pressure and speed up the healing process. Melanoma, on the other hand, requires immediate medical attention and treatment. Treatment options for melanoma include surgery, radiation therapy, and chemotherapy. The type of treatment recommended will depend on the stage and location of the melanoma.

Early detection is crucial for both blood blisters and melanoma. Blood blisters that do not heal or that appear in unusual locations should be examined by a doctor to rule out other underlying conditions. Melanoma should be diagnosed and treated as soon as possible to prevent it from spreading to other parts of the body. Regular skin exams and self-examinations can help to detect melanoma in its early stages.


Blood Blister



It is a raised, blood-filled sack on the skin.

It is a serious type of skin cancer.


  • Blood blisters are caused when something pinches your skin

  • Your hand caught in a door jamb

  • Wearing ill-fitted shoes that rub your skin

  • Viral infections – like chickenpox or shingles

  • Melanoma is caused when the pigment-producing cells which give colour to the skin become malignant or cancerous

  • A weak immune system

  • A family history of unusual moles or melanoma

  • Xeroderma pigmentosum – a rare genetic medical condition that stops the skin from repairing itself from Ultra Violet damage

  • Exposure to radiation, and some chemicals (e.g. solvents)


  • The blister looks like a friction blister

  • Blister may be red, purplish or even black in colour

  • Minor irritation at the site of the blister

  • Hard lumps beneath the skin

  • Pain in the bones

  • Advancement of pigment from the border of a spot to the surrounding skin

  • Change in the mole colour

  • Itchiness, redness, tenderness and pain

  • Oozing of blood from the mole

  • Scaliness and change in the surface of the mole

  • Height if the mole elevates and enlarges

  • Inflammation

  • Vision gets blurred or there is partial loss of sight, or even dark spots in the iris

Methods to reduce risk factors

  • Wear proper thick gloves when working with machines and tools or lifting heavy weights

  • In order to avoid blood blisters in feet, it is important to keep feet dry

  • Avoid wearing tight and uncomfortable shoes that do not fit.

  • Protect yourself from ultraviolet (UV) light exposure

  • People with fair skin, freckling, and light hair should keep monitoring their moles, any warts or lumps as they are at greater risk of getting melanoma.

  • People with weak immune system should take extra care.


  • Apply ice to the blood blister

  • Gently apply Aloe Vera gel to the blood blister for easing pain and swelling

  • Do not attempt to pop blood blister in order to avoid infection

  • Avoid to put pressure on the blister by wearing open-toe footwear.

  • Keep the area clean and exposed to air for faster healing

  • Protect the blister with a loose bandage for additional protection

  • Wrap the blister loosely to help avoid additional friction

  • Seek medical attention when required

  • Common medications used for melanoma include DTIC – Dome (dacarbazine), which is the only FDA-approved chemotherapy for melanoma. Methazolastone, Temodar (Temozolomide) is an oral version of DTIC, which is used for the treatment of stage four melanoma.

  • High dose radiation therapy

  • Surgery to remove tumours

  • Use of drugs that stimulate the body’s immune system to fight the melanoma. This treatment process is called immunotherapy


In conclusion, blood blisters and melanoma are two different skin conditions that can appear similar in their early stages. Blood blisters are usually caused by trauma or injury and usually heal on their own within a few days to a few weeks. Melanoma is a type of skin cancer caused by genetic mutations in melanocytes and requires immediate medical attention and treatment. Early detection and treatment are crucial for both blood blisters and melanoma to prevent complications and improve outcomes.

Updated on: 12-May-2023


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