The Difference Between Nail Fungus and Melanoma

Anju Mobin
By Anju Mobin
Joel Taylor
Edited by Joel Taylor

Published April 25, 2022.

A doctor wearing blue gloves inspecting a foot with nail fungus

Nail fungus is a common infection that affects the nail. Nail melanoma, on the other hand, is a type of skin cancer that develops in the skin under your nails. Although they may sometimes be confused, they are actually very different. Keep reading to understand the subtle difference between the two, their symptoms, causes, treatments, and more.

What Is Nail Fungus?

Nail fungus usually presents itself as a discoloration on the nails. You may find yellow-white spots on the nails that have become brittle or thicker.

Nail fungus, also known as Onychomycosis, is an infection that affects your nails, especially the toenails. It is caused by a fungus, the dermatophytes, and can be in, under, or on the nail (1).

Yeasts and molds can also cause nail infections. Nail fungus is more common in men than women and more common in adults than children. In this condition, your nails become brittle, discolored, and more likely to crack or break (2).

Who Is Most at Risk?

People who are most susceptible to nail infection are:

  • Elderly
  • Diabetics
  • Those with psoriasis
  • Those who sweat a lot
  • Those with PVD (peripheral vascular disease) with limited blood circulation to the hand and feet
  • Have a nail injury or skin injury surrounding the nail
  • Athletes
  • Those who use public areas
  • Those with a weak immune system

When Does It Occur?

Excessive sweating, usually in physically active people, is one of the most common causes of fungal toenail infections.

Fungi thrive in warm and humid conditions that might enter your body through a crack in the nail or surrounding skin. They are contagious and can spread by touching infected surfaces. For example, if you walk barefoot in an infected area such as your gym's locker room, shower room, or swimming pool, you can easily pick up the infection.

What Is Melanoma?

Nail melanoma presents itself as an irregular pigmentation of the nails. Often, it looks like a brown-black colored band, and it might be accompanied by pain.

Melanoma is a type of skin cancer that originates from the pigment-producing cells of the skin known as melanocytes (3). Nail melanoma, also known as subungual melanoma, is one of the most dangerous types of skin cancer if left untreated. It develops underneath the fingernail or toenail and is very uncommon, usually occurring in only 0.7 to 3.5% of malignant melanoma seen worldwide.

Who Is Most at Risk?

  • People in the age group of 50-70 years
  • African-Asian or Native American by origin
  • People who are mostly outdoors and are exposed to ultraviolet light
  • People with Dysplastic Nevus Syndrome (atypical mole syndrome)
  • Family history of melanoma
  • Having a weak immune system
  • People with Xeroderma pigmentosum, a rare, inherited condition that lowers the ability of the skin cells to repair damage to their DNA

When Does It Occur?

Nail melanoma begins in the nail matrix. It is a part of the nail bed that protects the skin under your nail (4). In most cases, it starts with an injury or trauma of the nail or the area around it, with the cause being the activation and proliferation of the melanocytes of the nail matrix. How and why exactly the subungual melanoma starts is still unknown.

How to Diagnose Nail Fungus and Melanoma

Diagnosing Nail Melanoma

Nail melanoma is very difficult to diagnose because of the similarity of its signs with other benign ones. They are usually (5):

  • Brown or black-pigmented band that is usually vertical on the nail
  • Change in skin pigmentation around the nail
  • Bleeding nail
  • Nail lesions
  • Nodule under the nail
  • Painful pus formation under the nail
  • Delayed healing
  • Separation of the nail from the nail bed

Even with nail injury or fungal infection, similar symptoms are detected. It is better to show your doctor for a proper diagnosis.

Diagnosing Nail Fungus

  • Nail discoloration
  • Thickened nail bed
  • Brittle nail

The right diagnosis can only be given by your healthcare provider as they may have to take your nail clipping to send for a fungal culture.

How to Treat Nail Fungus and Melanoma

Prevention is always better than cure, and the first thing is to maintain proper foot hygiene. You should also eat foods rich in antioxidants such as retinol and vitamin D. Retinol-rich foods such as dark green leafy vegetables, orange, and yellow fruits and vegetables, fish, eggs, etc., can reduce your chances of developing melanoma by 20%.

Nail Fungus Treatment

The most effective treatments for toenail fungus include:

  • Antifungal cream applied topically
  • Antifungal medications taken orally
  • Medicated nail polish or cream such as Fungix
  • Maintaining proper hand and feet hygiene
  • Keep your hands and feet dry and let them breathe
  • Use natural remedies for nail fungus such as Epsom salts, tea tree oil, and/or iodine

Melanoma Treatment

Nail melanoma or subungual melanoma is treated surgically. The other options are:

  • Removing the abdominal tissue
  • Immunotherapy
  • Chemotherapy
  • Radiation therapy
  • Amputation of the finger in the worst-case scenario

Should You See a Doctor for Nail Fungus or Melanoma?

Immediately go to your doctor if the self-care steps aren’t working. Red flags to watch out for include:

  • Toe swells
  • The nail has a greenish-black or reddish hue
  • painful
  • Warmth, tenderness, and extreme pain
  • Oozing pus
  • Pitting or deep gaps

Though nail fungus is pretty common, melanoma isn’t. If you feel that the signs exhibit a possible melanoma, show your doctor immediately. It's better to rule out cancer rather than get a late prognosis that will be more difficult to manage.