Small white spots on the arms or legs are quite common, and there are several possible causes. A specialist would usually look at the size, shape, texture, location, and whether they are changing before deciding what they are.
Common possibilities include:
- Idiopathic guttate hypomelanosis: Small, flat, white spots often seen on sun-exposed areas like the forearms and shins. They are harmless and become more common with age.
- Tinea versicolor: Light or white patches caused by an overgrowth of skin yeast; often appears on the chest, back, shoulders, or arms and may have mild scaling.
- Vitiligo: Areas where pigment-producing cells are reduced or absent, causing more sharply defined white patches that can grow over time.
- Dry skin or healed inflammation: Skin irritation, rashes, or minor injuries can sometimes leave lighter patches after healing.
It’s worth getting checked by a dermatologist if the spots:
- Are new and spreading
- Have sharp borders or are becoming completely white
- Are associated with itching, scaling, pain, or hair turning white in the area
- Appear suddenly or are changing quickly
A photo can help with a general discussion, but a clinician would need to examine the skin to identify the cause. If you describe the spots (size, exact location, how long they’ve been there, whether they are flat or raised, and whether they itch or peel), I can help narrow down the possibilities.
