White spots on the skin (also known as hypopigmentation or depigmentation) are caused by a decrease or loss of melanin, the natural pigment that gives color to the skin, hair, and eyes. This can have various causes, ranging from harmless and temporary problems to chronic conditions or autoimmune diseases. Most are not serious, but some require medical attention to confirm the diagnosis and rule out complications.
Main causes of white spots on the skin
Listed below are the most common, ranked from highest to lowest prevalence based on age and skin type:
- Idiopathic guttate hypomelanosis (sunspots or “white spots”)
is common after the age of 40-50, especially in people with fair skin.
They are small, round, white spots (2-6 mm) on the arms, legs, back, and hands.
Causes: cumulative sun exposure over the years + natural aging (melanocytes stop functioning in exposed areas).
They do not itch or cause pain; they are harmless but irreversible. - Pityriasis versicolor (or tinea versicolor)
is a fungal infection caused by fungi of the genus Malassezia (which normally occur on the skin but multiply rapidly in heat, sweat, and humidity).
It causes white, pink, or light brown spots on the chest, back, neck, and arms.
The spots are more visible after sun exposure (the fungus even blocks pigmentation).
There is usually mild itching or scaling. - A mild form of atopic dermatitis (eczema). It presents
as dry, scaly, round or oval white patches, primarily on the face (cheeks), neck, and arms.
It is common in children and adolescents but can also occur in adults with atopic dermatitis.
It is associated with dry skin, sun exposure, and a history of allergies.- Vitiligo is
an autoimmune disease in which the immune system attacks and destroys melanocytes. It manifests
as clearly defined, symmetrical white patches that can grow or merge.
It often begins on the hands, face, elbows, knees, or genitals.
It can occur at any age, but usually starts before the age of 30 or 40 (although there are also cases that develop later in life). - Post-inflammatory hypopigmentation occurs
after injuries or inflammations such as acne, burns, eczema, psoriasis, wounds, or dermatitis.
The healthy skin in these areas is lighter due to temporary damage to the melanocytes.
Usually, this recovers on its own over time and with sun protection.
- Vitiligo is
