What is inside a wart black dots?

Warts are small, rough, skin growths caused by the human papillomavirus (HPV). They often have a cauliflower-like appearance and can develop anywhere on the body. One of the most common characteristics of warts are the small, black dots that can be seen in the surface of the wart. But what exactly are these black dots inside of warts?

The black dots are clotted blood vessels

The black dots found on the surface of most warts are actually tiny clotted blood vessels. Warts are thickened areas of skin that form due to infection with HPV. As the virus causes abnormal cell growth, tiny blood vessels develop to supply the wart with blood and nutrients. These blood vessels tend to clot and can be seen as black or brown dots within the wart.

The medical term for these dots is thrombosed capillaries or thrombocytes. They form as a result of blood clotting and coagulation within the small blood vessels of the wart. As the clots get pushed toward the surface of the skin, they appear as black or brown dots visible on the exterior of the wart.

They are a key identifying feature of warts

The black dots are one of the unique identifying characteristics of a wart. In fact, the presence of thrombosed capillaries on the surface of a skin growth is one of the primary ways medical professionals diagnose warts.

If a growth has a rough, cauliflower-like texture and is covered by black dots, it is very likely a wart caused by HPV. The clotted capillaries distinguish warts from other benign growths like moles or skin tags which do not contain these dots.

So if you notice a new growth on your skin that is pale in color, dome-shaped, and covered in black dots, it is likely a wart. The dots differentiate warts from other lumps and bumps that can occur on the skin.

The dots often bleed when the wart is scraped

One unique thing about the thrombosed capillaries is that they often bleed when the wart is scraped or picked at. The clots essentially form scabs over the blood vessels. So disturbing the wart surface can open up the dot structure and lead to bleeding.

Often, people try to pick off warts or scrape the black dots. This almost always leads to bleeding from the capillaries as the clot scab is removed. That is why dermatologists recommend not picking at warts, as it can cause infection or spread the wart virus.

Some wart treatments target the clotted vessels

Since the black dots represent the small blood vessels feeding the wart, some treatments aim to disrupt the dots themselves. One example is salicylic acid, a common over-the-counter wart remover.

By applying salicylic acid regularly to a wart, it slowly breaks down skin cells and causes the black dot capillaries to dry up. Cutting off the blood supply can essentially starve the wart and cause it to gradually disappear.

Other in-office procedures like cryotherapy or laser treatment can also obliterate the dot structure to get rid of warts. So taking aim at the thrombosed capillaries is often an effective tactic.

The dots tend to disappear as the wart resolves

In most cases, the black dots will naturally disappear as a wart goes away. If the body’s immune system successfully fights off a wart, the virus will no longer trigger the abnormal capillary growth. As the wart shrinks and flattens, the clotted vessels will be reabsorbed into the skin and vanish.

So if you have a wart treated and notice the black dots gradually getting smaller and less pronounced, it is a sign the wart is clearing. The absence of the thrombosed capillaries usually means the wart has been eliminated.

Some key points about the black dots inside warts:

  • They are clotted blood vessels called thrombosed capillaries
  • Their presence is a key identifying feature of warts
  • Picking at the dots often causes bleeding
  • Wart treatments like salicylic acid target the vessels
  • The dots tend to disappear as the wart resolves

What Causes Warts?

Warts are caused by infection with one of over 100 types of the human papillomavirus (HPV). HPV causes an abnormal growth of epithelial cells on the skin, leading to the formation of a wart. The viruses are extremely contagious and spread through direct skin-to-skin contact or contact with infected surfaces.

HPV enters the body through small nicks or breaks in the skin barrier. It causes rapid multiplication of keratinocytes, leading to the characteristic thick, rough texture of a wart. While warts can occur anywhere on the body, they are especially common on hands and feet.

Certain strains of HPV are more likely to cause warts on different areas of the body:

  • HPV 2 and 4 often lead to common warts on hands
  • HPV 1, 2, and 4 frequently cause plantar warts on the feet
  • HPV 6 and 11 can cause genital warts

In most cases, the immune system will eventually mount a defense and clear the virus. But it can take weeks, months, or even years for warts to fully resolve untreated. The HPV virus nestles deep within the epithelial layers, causing them to proliferate wildly, which is why the immune response takes so long to control warts.

Who Gets Warts?

Anyone can develop common warts. Having direct, skin-to-skin contact with someone who has warts is the most common way they spread. Warts are extremely common, affecting an estimated 7 to 12% of the population.

Warts are often seen in children and teens but can occur at any age. Exposure to public places like swimming pools, locker rooms, and showers increases risk. People with weakened immune systems are also more prone to warts.

While harmless, warts can be embarrassing and often prompt people to want to remove them through treatment. Certain types of HPV are linked to rare cancers, but the strains that cause common warts do not increase cancer risk.

Signs and Symptoms of Warts

Warts can vary somewhat in appearance but generally share some common signs and symptoms:

  • Raised, rough, bumpy texture – they appear as small cauliflower-like skin growths
  • Dome, oval, or round shaped
  • Usually painless, unless located on joints or pressure points
  • Often have a surface pattern of tiny black dots (thrombosed capillaries)
  • Can occur as a single growth or in clusters/mosaics
  • Common locations include hands, fingers, feet, knees, elbows

In some cases, warts may take on slightly different appearances depending on their location. For example:

  • Plantar warts on feet – thickened, flat, with pattern of brown/black dots
  • Periungal warts – small bumps at nail base
  • Filiform warts – long, narrow shape on face or neck

If an unusual skin growth matches the common wart characteristics, it can be diagnosed clinically by a doctor. In uncertain cases, they may biopsy the growth to test for HPV virus.

Are Warts Contagious?

Yes, warts are highly contagious and spread through direct contact. The HPV virus that causes warts can linger on surfaces and enter through tiny nicks or scratches in the skin. Common ways warts spread include:

  • Skin-to-skin contact with someone who has warts
  • Using towels, razors, or other items used by an infected person
  • Touching dirty surfaces like locker room or pool floors
  • Biting fingers/nails and spreading virus to other areas

Warts commonly spread to other areas of the infected person’s body through touch. Auto-inoculation allows the virus to spread to additional locations.

To prevent spreading warts:

  • Avoid direct contact with warts when possible
  • Do not share personal items like towels or razors
  • Keep warts covered with bandages or duct tape
  • Practice good hygiene and wash hands frequently

While highly contagious, having contact with HPV will not necessarily guarantee infection. The virus must get access through a break in the skin to initiate wart formation. But it is smart to avoid contact when feasible.

How to Get Rid of Warts

While warts often clear eventually on their own, most people want to get rid of them fast. There are a variety of effective wart removal options, including:

  • Salicylic Acid – This is an over-the-counter medication used frequently for wart removal. The acid kills infected skin cells and may dry out clotted capillaries.
  • Cryotherapy – Freezing warts with liquid nitrogen applied by a medical provider. Can destroy abnormal tissues quickly when applied correctly.
  • Cantharidin – A topical blistering agent applied in a doctor’s office. Causes wart tissue to die off painlessly.
  • Laser Therapy – Using focused light to bombard and destroy wart tissues.
  • Electrosurgery – Burning off warts with electrical current/cauterization.
  • Duct Tape Occlusion – Covering warts with adhesive duct tape to shut off air supply.

While treatment works well in most cases, warts can be stubborn. It often takes weeks to months of repeated applications like salicylic acid to fully clear them. Patience is key.

Over-the-counter freezing sprays can be used on most warts. But certain sensitive areas like the face or genitals require care by a dermatologist. They can properly assess the warts and select the most appropriate removal approach.

How to Prevent Warts

It is difficult to fully prevent warts since the HPV virus spreads easily through casual skin contact. However, some measures can reduce your risk of developing warts:

  • Avoid direct contact with existing warts and avoid picking/scratching them
  • Keep your immune system strong through diet, exercise, sleep
  • Do not share personal care items like towels or razors
  • Wear water shoes in public showers/locker rooms
  • Disinfect surfaces infected individuals have touched
  • Get children/teens vaccinated against HPV strains that cause warts

Using common sense hygiene and avoiding contact with warts when possible can decrease your risk. However, HPV is so prevalent there is no way to fully prevent exposure.

Can Warts Go Away on Their Own?

Yes, warts frequently go away on their own without any treatment. The body’s immune system targets foreign HPV virus proteins within the wart. White blood cells gradually develop antibodies that can destroy the infection.

In healthy people, most warts resolve spontaneously within months to a few years. About 65% disappear within 2 years. However, in some cases, warts can persist for many years.

It is not recommended to simply leave warts alone hoping they will vanish. Proactive treatment with options like salicylic acid typically speeds up their resolution.

Certain people are more prone to having warts persist for long periods or spread:

  • Those with weakened immune systems
  • People taking immunosuppressant medications
  • Individuals with diseases like HIV or leukemia
  • Those with prior HPV infections/warts
  • Smokers – smoking impairs immune function

While waiting carries a good chance of eventual resolution, treatment is advised to quickly destroy warts and minimize spread.

Are Warts Dangerous?

Warts themselves are harmless growths and more of a cosmetic nuisance than medical issue. They do not turn cancerous or place your health at risk.

However, the HPV virus that triggers warts in some of its strains can cause problems like:

  • Rare cancers (cervical, anal, oral, etc.) from high risk HPV types
  • Genital warts (condyloma) from sexually transmitted strains
  • Recurrent Respiratory Papillomatosis (warts in throat)

The strains that cause common cutaneous warts do not increase cancer risks or cause other issues. Still, wart presence does indicate active HPV infection, which is why treatment helps clear the virus.

When to See a Doctor for Warts

Most common warts can be self-treated with over-the-counter remedies like salicylic acid. But it is a good idea to have your warts examined by a doctor if:

  • They are widespread and not responding to self-treatment
  • The warts change appearance or seem unusual
  • They are located on the face, neck, or genital region
  • They are painful or growing rapidly
  • Your immune system is weakened from illness or medications
  • You are diabetic – diabetes impairs wound healing

Dermatologists can provide prescription-strength wart removal medications and use specialized techniques like cryotherapy or laser. For stubborn warts, professional treatment is advised.


The black dots seen in warts are actually thrombosed capillaries – tiny blood vessels that have clotted. Their presence is characteristic of warts and they often bleed if scratched or scraped. While harmless, warts should be treated to avoid spreading the highly contagious HPV virus. Using salicylic acid, cryotherapy, laser, or electrosurgery can safely get rid of warts in most cases.

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