Small white spots on the arms or legs are fairly common, and there are several possible causes. The meaning depends on the size, texture, location, how long they’ve been there, and whether they are changing.
Common possibilities include:
- Sun-related white spots (idiopathic guttate hypomelanosis): Small, flat, lighter-colored spots often seen on sun-exposed areas, especially with age.
- Dry skin or mild irritation: Can make areas look lighter, especially if the skin is flaky or rough.
- Tinea versicolor: A fungal skin condition that can cause lighter (or darker) patches, sometimes with fine scaling.
- Vitiligo: A condition where areas of skin lose pigment, usually creating more clearly defined white patches that can gradually expand.
- Post-inflammatory hypopigmentation: Lighter spots that appear after healing from a rash, injury, or inflammation.
A few things to check:
- Are the spots pure white or just lighter than your skin?
- Are they flat, raised, itchy, or scaly?
- Did they appear suddenly or slowly over time?
- Are they spreading or appearing in new areas?
If the spots are rapidly spreading, involve hair turning white in those areas, are associated with other symptoms, or you’re unsure of the cause, a dermatologist can help identify them.
If you describe the spots (size, location, age when they started, and whether they itch or have scaling), I can help narrow down the possibilities.
