- White spots on your skin can signal idiopathic guttate hypomelanosis, a result of UV exposure.
- They may also be leftover scars from eczema or tinea versicolor, a fungal infection.
- Flat warts look like light-colored shiny patches that are caused by HPV.
- Visit Insider's Health Reference library for more advice.
Sometimes, white spots that crop up on your skin can be harmless — but other times, they could signal a serious condition.
That's why, it's important to take note of other symptoms you may experience and the exact appearance of the spots so that you can help your doctor identify the cause.
Here are eight causes of white spots on the skin, and how to treat them.
1. Idiopathic guttate hypomelanosis (IGH)
While most people associate sun spots with a darker pigment, white spots can also be a result of UV exposure. This is known as idiopathic guttate hypomelanosis.
The condition results in smooth, asymptomatic white spots that most commonly appear on the arms or legs, says Emily Wood, MD, board-certified dermatologist at Westlake Dermatology.
Genetics can make you more predisposed to IGH, too, Wood says. For example, if your parents have IGH, you are more likely to have it as well.
How to treat it: Treatment for this benign condition is not necessary unless the cosmetic aspect bothers you. In this case, your dermatologist might suggest cryotherapy, chemical peels, or topical steroids — but success is limited, Wood says. To prevent further spots from developing, be sure to always wear sunscreen.
2. Milia
Milia are small, shiny white bumps that typically occur around the eyes and mouth, says Wood.
They are caused by a buildup of trapped keratin, a type of protein that makes up skin cells. These spots are most common in newborns, but can affect people of all ages.
How to treat it: Since milia are harmless, treatment isn't necessary unless you are bothered by the appearance. In this case, Wood suggests seeing your dermatologist who can extract the milla. Additionally, Wood says you can prevent new milia from developing by using a gentle chemical exfoliant such as a BHA or AHA a few times a week.
3. Eczema (atopic dermatitis)
Eczema is a chronic condition characterized by dry, itchy, red skin. While white spots are not a direct sign of eczema, they may still show up.
"Severe scratching can lead to change in skin color, sometimes causing white spots which can be permanent," says Barry Goldman MD, board-certified dermatologist at Goldman Dermatology and clinical instructor at Weill Cornell Medicine.
Alternatively, eczema may present as pink scaly patches that then fade to a hypopigmented (lighter colored) patch, says Wood.
How to treat it: Moisturizing your skin is key to managing the dryness and itchiness of eczema, says Wood. Other eczema treatments include:
- Corticosteroid cream
- Oral corticosteroids
- Injectable biologics (in severe cases)
4. Tinea versicolor
This is a fungal infection caused by an overgrowth of a type of yeast found on the skin called malassezia. Goldman says this affects pigment production in your skin, leading to hypopigmented white spots.
Typically you will see these white spots on your torso area, and it's most common in people with oily skin or people who live in hot, humid climates, says Goldman. This is because the moist and oily skin can contribute to yeast growth.
How to treat it: Since tinea versicolor is a fungal infection, it requires treatment with antifungal medications, either topically or orally in more severe cases. You must be patient during treatment as even after the fungus clears up, it can take weeks or even months for the hypopigmentation to resolve.
5. Vitiligo
Vitiligo is a chronic autoimmune disease. Goldman says with this condition, the body's immune system attacks melanocytes, which are skin cells that produce melanin, or pigment in the skin.
This results in loss of pigment in the skin and white spots or larger patches of discoloration. It may affect people of any age or race, and it's sometimes associated with other autoimmune disorders, Goldman says.
How to treat it: There's no cure for this condition, but there are treatments that may help with the hypopigmentation. These treatment options include:
- Corticosteroids (oral or topical)
- Immunomodulators
- Topical vitamin D analogs which work to modulate the immune system and inflammatory responses
- Light/laser therapy
- Skin graft surgery
6. Nevus depigmentosus
If you've had a white spot or patch ever since you were a baby, chances are, it's a benign type of birthmark.
"Typically present since birth or within the first few years of life, a nevus depigmentosus is a birthmark that has less pigment than surrounding skin," says Wood. This is not progressive, meaning it won't get worse with time, and is asymptomatic.
How to treat it: Treatment is not necessary, and cosmetic treatments usually have limited success, says Wood. However, laser therapy can be attempted to correct the pigmentation.
7. Flat warts
Flat warts may present as a cluster of white or pinkish shiny papules, which are caused by the human papilloma virus (HPV), says Wood.
Most often they are asymptomatic, but can be a bother cosmetically and they can also easily spread. In men, they often show up in the beard area and on women, on the legs.
How to treat it: Treatment is important to keep the warts from spreading. Treatment options include:
- Salicylic acid
- Cryotherapy (freezing the warts)
- Paring (cutting or scraping the warts)
- Injections
- Lasers
Additionally, if you are dealing with warts in an area where you shave, be sure to use clean razors to prevent new warts from forming, says Wood.
8. Skin cancer
If you have a white spot that changes in size or texture, such as if it has a waxy appearance and an undefined border, Goldman says you should see a dermatologist to rule out skin cancer.
This may be a type of skin cancer called basal cell carcinoma. There are around 3.6 million cases of basal cell carcinoma diagnosed annually in the United States, making it the most common skin cancer.
How to treat it: First, a biopsy is necessary to confirm the diagnosis. If skin cancer is confirmed, common treatment options include:
- Surgery
- Curettage and electrodessication
- Cryosurgery (freezing)
- Radiation therapy
Insider's takeaway
There's a wide range of causes for white spots on the skin, ranging from harmless to more serious. It's important to see a dermatologist for a proper diagnosis so that you can start the correct course of treatment.