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Last Updated on April 18, 2024

Flat warts are a common skin condition characterized by small, smooth, slightly raised bumps. Often appearing on the face, hands, wrists, and knees. While generally harmless, flat warts can be bothersome and potentially contagious.Interestingly, specific strains of HPV primarily cause flat warts by targeting the top layer of the skin. This results in their distinct flat appearance, which sets them apart from other wart types caused by the human papillomavirus (HPV).

In this blog, we will explore the causes, risk factors, diagnosis, treatment options, and preventive measures related to flat warts. Understanding these aspects is crucial for effectively managing and dealing with certain skin conditions, whether you have them yourself or seeking information for someone else.

What are Flat Warts?

Flat warts, also known as verruca plana, are a common type of wart that typically appears as small, smooth, flat-topped growths on the skin. These warts are caused by the human papillomavirus (HPV) and can occur in various areas of the body. In this blog, we will explore what flat warts look like, their causes, risk factors, diagnosis, and effective treatment options.

What Do Flat Warts Look Like?

Flat warts typically measure 1-5 millimeters in width and are slightly raised with a round or oval shape. They usually blend in with the skin color but may also appear pink or yellow brown. These warts often cluster together in groups of 20 to 100, making them noticeable despite their small size. They commonly appear on the face, legs, and back of the hands.

One of the distinguishing features is their color, which can range from flesh-colored to slightly yellow or brown. They may also appear translucent, making them less noticeable compared to raised warts. warts commonly develop on the face, neck, hands, wrists, and knees, but they can occur on any part of the body.

Causes and Risk Factors

The HPV specifically strains 3, 10, 28, and 49 are primary cause of flat warts. These strains are highly contagious and can spread through direct skin-to-skin contact or contact with contaminated objects. Factors that increase the risk of developing include:

Weakened Immune System:

Individuals with a weakened immune system due to conditions like HIV/AIDS or immunosuppressive medications are more susceptible to HPV infections.

Skin Trauma:

Warts are more likely to develop on skin that has been damaged or injured, such as cuts, scrapes, or shaving nicks.


Flat warts are more common in children and young adults, although they can affect individuals of any age.

Poor Hygiene:

Not washing hands regularly or sharing personal items, can increase the risk of acquiring warts due to the contagious nature of HPV. Occupational Exposure Certain occupations or activities that involve frequent skin contact or exposure to HPV-infected surfaces may increase the risk of developing.

Similar Skin Condition

Flat warts can be mistaken for other skin conditions due to their appearance. Brown may resemble age spots or small moles, while pink ones could be confused with acne.

When comparing to skin tags, the key difference lies in their attachment to the skin. Skin tags are frequently characterized by a stalk connecting them to the skin, making them easily distinguishable from other skin growths. They commonly appear in areas with skin folds such as the eyelids, underarms, and beneath the breasts.

Milia are small cysts found on the face. It shares similarities with flat warts in terms of size and color. However, milia are firm, domed-shaped bumps compared to the flat top of warts. Additionally, milia are typically pearl-colored and mainly occur on the face.

Seborrheic keratoses are another benign skin growth. It can resemble but has a rough, lumpy surface and may appear scaly or waxy. They are usually light tan, brown, or black in color.


Flat warts are typically diagnosed through a visual examination by a healthcare professional. Their flat and smooth appearance makes them easy to identify compared to other skin growths.

However, if there’s uncertainty or the warts are large or unusual, a dermatologist may suggest a skin biopsy. This procedure involves taking a small sample of tissue from the wart to confirm the diagnosis. It’s especially useful when the diagnosis isn’t clear just by looking at the warts.

Treatment Options

While flat warts may resolve on their own over time, treatment is often recommended to speed up the healing process, reduce the risk of spreading, and alleviate any discomfort or cosmetic concerns. Additionally, some ongoing clinical trials are working on a permanent solution for warts.

However, sometimes warts may reappear in other places or spread regardless of the treatment. Furthermore, some treatments can be painful and cause scarring also.

Here are some effective treatment options:

Topical Treatments

  • Prescription creams:

Tretinoin, imiquimod 5% cream, and 5% benzoyl-peroxide are effective in treating warts over time.

  • Over-the-counter:

Medication containing salicylic acid or keratolytic agents can also be applied directly to the warts for dissolution over time.

Professional Treatments:


This in-office procedure involves freezing the wart with liquid nitrogen, causing it to blister and eventually fall off. It’s a popular option for multiple warts, but repeated treatments may be necessary.


Using an electric current, a dermatologist removes the wart with precise control. This method is suitable for stubborn warts or those in sensitive areas.


A topical medication applied by a doctor, cantharidin creates a blister underneath the wart, causing it to detach. This option requires follow-up visits to remove the loosened wart tissue.

Laser Therapy:

This method uses a concentrated beam of light to destroy the wart tissue. While effective, it may leave slight scarring and might be more expensive than other options.


It may be prescribed to stimulate the body’s immune response and help clear the warts. Examples of immunotherapy for flat warts include imiquimod cream or injection of candida antigen.

Home Remedies

While not as effective as medical treatments, some individuals may try home remedies such as applying apple cider vinegar to the warts. However, it’s essential to consult with a healthcare professional before attempting any home remedies to ensure safety and efficacy.

Prevention Tips

To reduce the risk of developing flat warts and other HPV-related infections, consider the following preventive measures:

  • Practice good hygiene, including frequent handwashing.
  • Avoid touching or picking at warts to prevent spreading.
  • Use protective footwear in communal areas like swimming pools or locker rooms.
  • Keep skin cuts, scrapes, and injuries clean and covered.
  • Consider vaccination against HPV, especially for individuals at higher risk.

How long do Warts Take to Disappear?

The time for flat warts to disappear varies depending on several factors such as your overall health, the type of wart, and the area affected.

Typically, flat warts can resolve on their own within a timeframe ranging from one to two months up to two years. Studies suggest that approximately 23% of warts disappear within two months, 30 % within three months, and up to 78% within two years.


Flat warts are generally harmless but can be bothersome and affect one’s self esteem. Fortunately, various effective treatment options are available to manage and remove flat warts.

Moreover, if you suspect you have warts or any other skin concerns, it’s essential to consult with a dermatologist for an accurate diagnosis and appropriate treatment plan.

While established treatments like salicylic acid and cryotherapy offer effective solutions, the world of dermatology is constantly evolving. Clinical trials offer a unique opportunity to explore cutting-edge treatment options that may not yet be widely available. With proper care and treatment, you can achieve clear, healthy skin and peace of mind.


MetroBoston Clinical Partners is a well established and experienced research center in the greater Boston area. Under the leadership of qualified physicians and medical professionals, we coordinate a range of clinical research trials in Dermatology and Internal Medicine.

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