White spots on the skin often occur when skin proteins or dead cells become trapped under the skin's surface. They may also occur as a result of depigmentation, or color loss.
White skin spots are not usually a reason for concern and do not cause major symptoms.
It is important, however, to have white spots checked by a dermatologist, to understand their cause and the best way to treat them.
A variety of health conditions and factors can cause white spots to develop on different parts of the body.
Common causes of white spots on the skin include:
Sunspots, or guttate hypomelanosis
Sunspots are white spots where skin pigment has been lost.
These spots usually cause no symptoms, are 1–3 millimeters (mm) in size, and tend to appear first on the legs before progressing to the arms, upper back, and face.
Researchers are not sure what causes sunspots. Causes might include a lack of a skin pigment called melanin. Sunspots also seem to run in families. They are more likely to appear after the age of 40 years.
However, they are harmless, and treating them is a cosmetic issue.
Tinea versicolor, or pityriasis versicolor
In people with tinea versicolor (TV), the fungus that usually lives on the skin's surface grows out of control.
The fungus causes dry, scaly, itchy patches that are either lighter or darker than surrounding skin. These patches usually grow fairly slowly and often cluster together.
Sometimes, symptoms of TV may only be noticeable when a person has a suntan. The condition is widespread, and symptoms tend to become more noticeable in warm, humid environments.
Pityriasis alba (PA) is a relatively widespread, non-cancerous skin condition that causes red, scaly, itchy patches. These patches eventually heal and leave behind faint, white spots.
PA tends to develop in children between the ages of 3 and 16 and usually affects the face, but can also impact the neck, shoulders, and arms.
Researchers are not sure what causes PA, but they think it may be a mild form of atopic dermatitis or eczema.
Pigmenting pityriasis alba is a rare though potentially under-reported form of PA. It causes bluish-white scaly patches that are outlined by a patch of very light skin.
Like PA, pigmenting pityriasis alba mostly affects the face and tends to develop in children.
In people with vitiligo, white skin patches appear in places where the cells that make skin pigment, or color, have been destroyed.
Researchers are not sure what causes vitiligo. It may be an autoimmune condition, where the immune system mistakenly harms healthy cells.
White patches tend to develop in places exposed to the sun and may develop slowly or spread quickly. Vitiligo seems to run in families, and most people first notice skin discoloration in their 20s.
Milia are firm, raised, painless, white, fluid-filled sacs, between 1–4 mm wide that develop on the surface of the skin.
Primary milia occur randomly, when keratin, a protein that helps harden the outer layer of the skin, becomes trapped under the skin and forms a fluid-filled sac.
Secondary milia develop as a result of trauma from events, such as dermabrasion, tissue damage, blistering, and skin inflammation. Secondary milia may also occur as a side effect of some medications.
Though very rare, a condition called milia en plaque causes milia surrounded by areas of raised, red, scaly, itchy skin. Milia en plaque tends to occur randomly in healthy skin and currently has no known cause.
Researchers, however, think that milia en plaque may be a sign of discoid lupus erythematosus, a long-term skin condition that causes inflamed sores and scarring on the face, scalp, and ears.
Most people with guttate hypomelanosis have fair skin and have had years of continual or excessive sun exposure.
The preferred treatment for white spots on the skin depends on the cause of the spots.
Sunspots do not typically cause any symptoms aside from changing the color of the skin, and many people decide not to treat it.
For cases where white spots are very noticeable or cover a significant portion of the body, treatment may be appropriate.
Treatment options include:
- wearing sunscreen every day, covering all areas of skin exposed to the sun. Compare various brands online.
- avoiding spending too long in the sun
- avoiding artificial tanning beds
- dermabrasion, which physically removes the outer layers of skin
- topical steroid creams, such as hydrocortisone, available to purchase online.
- topical retinoid creams, such as retinol and tretinoin
Steroid and retinoid creams cause cell turnover and the removal of the outer layers of skin.
Symptoms of PA can resolve on their own. Many people do not seek treatment aside from the resulting skin discoloration or itchiness.
Several medications to be applied to the skin may be prescribed to reduce inflammation, itchiness, and dryness associated with PA.
Treatment options for PA include:
- regular use of moisturizers
- low-dose topical corticosteroid creams, often starting with 1-percent hydrocortisone cream. These can be purchased over-the-counter or online.
- Elidel cream, a nonsteroidal formula
Antifungal shampoos washes, soaps, and creams are usually the first line of treatment. These are available to purchase over-the-counter or online. Most antifungal medicines contain selenium sulfide, pyrithione zinc, or ketoconazole.
Once symptoms have gone away, further antifungal treatments may be necessary each month in hot environments or during the spring and summer months.
If a significant portion of the skin is affected or is not responsive to topical medications, doctors may prescribe antifungal pills for a short period. It often takes months for the skin to regain its normal color once the spots have cleared.
Vitiligo tends to affect large portions of the skin and causes significant skin discoloration. This may lead to emotional distress.
Depending on the severity of white patches, and how the person feels about their appearance, several treatment options may be used to help reduce or limit vitiligo symptoms.
If symptoms are very minor, some people can prevent white patches from becoming obvious by not allowing their skin to tan.
Treatment options for vitiligo include:
- low-dose corticosteroid creams, like 1-percent hydrocortisone cream
- Elidel cream, a nonsteroidal formula
- ultraviolet light treatment in combination with topical medications
- bleaching the skin surrounding large white patches to blend them
- tattooing over white patches
- surgery to remove the upper portions of affected skin, if medications and light therapy fail
For milia, retinoid creams and ointments, especially those with 0.1 percent tretinoin, are normally the first recommended line of treatment. These can be purchased over-the-counter or online.
Steroid creams are also commonly prescribed to help reduce or remove milia.
In most cases, white spots on the skin do not require medical treatment.
However, it is important to have white spots checked by a dermatologist to rule out any underlying conditions.
People are also advised to talk with a doctor about white spots if they:
- remain after a few weeks of basic treatment
- continuously reappear
- spread to other parts of the body
- cause symptoms, such as pain, itchiness, or emotional distress